Photosensitive resin composition, light-shielding color filter and production process therefor, and image sensor

ABSTRACT

A photosensitive resin composition is provided that includes at least (A) titanium black, (B) a polymerizable compound, (C) a photopolymerization initiator (D) a resin, and (E) an organic solvent, the photopolymerization initiator (C) using in combination two or more types of photopolymerization initiators including at least one type of oxime-based photopolymerization initiator. There are also provided a light-shielding color filter having a pattern formed by using the photosensitive resin composition, a process for producing a light-shielding color filter that includes a step of coating a substrate with the photosensitive resin composition, a step of imagewise exposing, and a step of developing to form a pattern, and an image sensor having the light-shielding color filter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a photosensitive resin composition, alight-shielding color filter and a production process therefor, and animage sensor.

2. Description of the Related Art

A color filter used in a liquid crystal display device comprises alight-shielding film called a black matrix for the purpose of improvingcontrast by shielding light between color pixels, etc. Furthermore, inan image sensor which is also called a solid-state image sensor, alight-shielding film is provided for the purpose of preventing theoccurrence of dark current (noise) due to stray light and improvingimage quality.

As a composition for forming a black matrix for a liquid crystal displaydevice or a light-shielding film for an image sensor, a photosensitiveresin composition comprising a black color material such as carbon blackor titanium black is known (ref. e.g. JP-A-10-246955, JP-A-9-54431,JP-A-10-46042, JP-A-2006-36750, and JP-A-2007-115921) (JP-A denotes aJapanese unexamined patent application publication).

BRIEF SUMMARY OF THE INVENTION

As a black matrix for a liquid crystal display device, light-shieldingproperties in mainly the visible region are required, whereas as alight-shielding film for an image sensor (hereinafter, synonymous with‘light-shielding color filter’), in addition to light-shieldingproperties in the visible region, it is necessary to havelight-shielding properties in the IR region.

Furthermore, a black matrix for a liquid crystal display device isrequired to be microfabricated, whereas a light-shielding film for animage sensor (solid-state image sensor) is required to have a capabilityof shielding light evenly over the whole area of a wafer. As alight-shielding film for an image sensor, it is important to have alight-shielding film disposed on an image pickup section periphery,which is a region around the image pickup section (effective pixelregion) and/or a light-shielding film disposed between protrudingelectrodes on a reverse face opposite to a surface on which the imagepickup section is formed.

However, when as a light-shielding film for an image sensor alight-shielding film is formed on a pattern having a step within a planeusing the above-mentioned known photosensitive resin composition, thefilm thickness of the light-shielding film tends to become thinner in awafer peripheral section than in a wafer central section, and thelight-shielding performance of the element in the wafer peripheralsection can sometimes become low.

Furthermore, there is the problem that adhesion between a substrate anda light-shielding film is insufficient, and as a result of chipping orpeeling of the light-shielding film, the light-shielding performancebecomes low. The present invention has been accomplished in the light ofthe above-mentioned problems.

It is an object of the present invention to provide a photosensitiveresin composition that can form a light-shielding color filter havingexcellent resolving power, excellent adhesion to a substrate, andexcellent coating thickness uniformity on a substrate, a light-shieldingcolor filter formed by using the photosensitive resin composition and aproduction process therefor, and an image sensor comprising thelight-shielding color filter.

The objects of the present invention have been attained by meansdescribed in (1), and (7) to (9) below. They are described belowtogether with (2) to (6), which are preferred embodiments.

-   (1) A photosensitive resin composition comprising at least (A)    titanium black, (B) a polymerizable compound, (C) a    photopolymerization initiator, (D) a resin, and (E) an organic    solvent, the photopolymerization initiator (C) comprising in    combination two or more types of photopolymerization initiators    including at least one type of oxime-based photopolymerization    initiator,-   (2) the photosensitive resin composition according to (1) above,    wherein the oxime-based photopolymerization initiator is an oxime    ester-based photopolymerization initiator,-   (3) the photosensitive resin composition according to (1) or (2)    above, wherein the oxime-based photopolymerization initiator    comprises    2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,    1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,    or a compound represented by Formula (1) below

(in Formula (1), R and B independently denote a monovalent substituent,A denotes a divalent organic group, and Ar denotes an aryl group),

-   (4) the photosensitive resin composition according to any one of (1)    to (3) above, wherein the photopolymerization initiator (C)    comprises    2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and    1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,-   (5) the photosensitive resin composition according to any one of (1)    to (4) above, wherein the photopolymerization initiator (C)    comprises in combination    2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and    1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone    at a molar ratio of 1/9 to 9/1,-   (6) the photosensitive resin composition according to any one of (1)    to (5) above, wherein it is intended for use in an image sensor,-   (7) a light-shielding color filter comprising a pattern formed by    using the photosensitive resin composition according to any one    of (1) to (6) above,-   (8) a process for producing a light-shielding color filter, the    process comprising a step of coating a substrate with the    photosensitive resin composition according to any one of (1) to (6)    above, a step of imagewise exposing, and a step of developing to    form a pattern, and-   (9) an image sensor comprising the light-shielding color filter    according to (7) above.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A sectional view showing one example of an image pickup sectionand a light-shielding section disposed on the periphery in the imagesensor of the present invention.

FIG. 2 A schematic plan view showing one example of a solid-state imagepickup device comprising the image sensor of the present invention.

FIG. 3 A sectional view of one example of a solid-state image pickupdevice comprising the image sensor of the present invention.

EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS

-   1: Image sensor-   2: Image pickup section-   3: Light shielding section-   4R, 4G, 4B: Color filter-   5: Light-shielding color filter-   10: Silicon substrate-   12: Photoelectric transducer (light-receiving sensor section)-   14 a, 14 b: Transfer electrode-   16: Insulating film-   17: Microlens-   18 a, 18 b: Planarization layer-   20: Image pickup device-   21: Wiring board-   22: Image pickup chip-   23: Light-shielding color filter-   24: Image sensor-   25: Underfill resin-   26: Protruding electrode-   27: Through electrode-   30: Bonding pad-   50: Solder ball

DETAILED DESCRIPTION OF THE INVENTION

(1) Photosensitive Resin Composition

The photosensitive resin composition of the present invention comprises(A) titanium black, (B) a polymerizable compound, (C) aphotopolymerization initiator, (D) a resin, and (E) an organic solvent,the photopolymerization initiator (C) comprising in combination two ormore types of photopolymerization initiators including at least one typeof oxime-based photopolymerization initiator.

The photosensitive resin composition of the present invention maycomprise another component as an additive in addition to components (A)to (E) above.

Furthermore, the photosensitive resin composition of the presentinvention may be suitably used as a photosensitive resin composition foran image sensor, and may be suitably used in order to form alight-shielding color filter (light-shielding film) in an image sensor.

Each component of the photosensitive resin composition of the presentinvention is explained below.

(A) Titanium Black

The photosensitive resin composition of the present invention comprisestitanium black as a black color material (black colorant).

Since titanium black has high light-shielding capacity in the IR regioncompared with conventional pigments and dyes that are dispersed ordissolved in a photosensitive resin composition, in particular aphotosensitive resin composition for a color filter, light shielding inthe IR region, which cannot be carried out by superimposition of colorfilters, can be carried out reliably. In particular, a light-shieldingfilm formed by curing the photosensitive resin composition of thepresent invention has high light-shielding properties in the IR region,and noise due to dark current in an image sensor equipped with thelight-shielding film can be suppressed.

Furthermore, compared with carbon black, which is generally used as ablack color material, titanium black has little absorption of i rayirradiation (mercury i rays, 365 nm) used for formation of a pattern,and curing can be carried out with a smaller amount of exposure when irays are used for exposure, thus contributing to an improvement inproductivity.

Titanium black comprises titanium atom-containing black particles. It ispreferably low valence titanium oxide, titanium oxynitride, etc.

The surface of titanium black particles can be chemically modified asnecessary for the purpose of improving dispersibility, suppressingaggregability, etc. Specifically, the surface of titanium black can becovered with silicon oxide, titanium oxide, germanium oxide, aluminumoxide, magnesium oxide, or zirconium oxide, and it is also possible tocarry out a surface treatment with a water-repellent material such asthat shown in JP-A-2007-302836.

Furthermore, for the purpose of adjusting dispersibility, colorationproperties, etc., the titanium black may comprise one type of blackpigment such as a composite oxide of Cu, Fe, Mn, V, Ni, etc., cobaltoxide, iron oxide, carbon black, or aniline black, or two or more typesthereof in combination.

Moreover, for the purpose of controlling light-shielding properties at adesired wavelength, an existing colorant such as a red, blue, green,yellow, cyan, magenta, violet, orange, etc. pigment or dye may be added.

Examples of commercially available titanium black include titanium black10S, 12S, 13R, 13M, 13M-C, 13R, and 13R-N manufactured by Jemco Inc.(sold by Mitsubishi Materials Corporation), and Tilack D manufactured byAko Kasei Co., Ltd.

As a process for producing the titanium black, there are a process inwhich a mixture of titanium dioxide and metallic titanium is heated in areducing atmosphere, thus carrying out reduction (JP-A-49-5432), aprocess in which ultrafine titanium dioxide obtained by high temperaturehydrolysis of titanium tetrachloride is reduced in a reducing atmospherecontaining hydrogen (JP-A-57-205322), a process in which titaniumdioxide or titanium hydroxide is reduced at high temperature in thepresence of ammonia (JP-A-60-65069, JP-A-61-201610), a process in whicha vanadium compound is deposited on titanium dioxide or titaniumhydroxide, and a high temperature reduction is carried out in thepresence of ammonia (JP-A-61-201610), etc. and the process is notlimited thereto.

The particle size of the titanium black particles is not particularlylimited, but from the viewpoint of dispersibility and colorationproperties and from the viewpoint of influence on yield for an imagesensor, the average particle size (average primary particle size) ispreferably 10 to 150 nm, more preferably 50 to 100 nm, and particularlypreferably 80 to 100 nm.

The average particle size of titanium black may be measured by coatingan appropriate substrate therewith and examining with a scanningelectron microscope.

The specific surface area of the titanium black is not particularlylimited, but in order to obtain predetermined performance for waterrepellency after titanium black is surface-treated with a waterrepellant, a value measured by a BET method is preferably about 5 to 150m²/g, and more preferably about 20 to 100 m²/g.

In the present invention, titanium black and another black colormaterial may be used in combination, and with regard to the black colormaterial other than titanium black, one type thereof may be used on itsown or two or more types thereof may be used in combination.

As a black color material that can be used in combination, various knownblack pigments or black dyes may be used, and from the viewpoint ofrealizing high optical density with a small amount, carbon black, ironoxide, manganese oxide, graphite, etc. are particularly preferable, andamong them carbon black is preferable.

The carbon black is in the form of black fine particles comprisingcarbon fine particles, and preferred particles comprise carbon fineparticles having a diameter of about 3 to 1,000 nm. Furthermore, thesurface of the fine particles may have various types of functionalgroups containing a carbon atom, a hydrogen atom, an oxygen atom, asulfur atom, a nitrogen atom, a halogen, an inorganic atom, etc.

Moreover, the properties of carbon black may be changed according to anintended application by variously changing particle size (dimensions ofparticle), structure (connection of particles), and surface properties(functional group). It is also possible to change the degree ofblackness or affinity for a resin, or impart electroconductivity.

Specific examples of the carbon black include Carbon Black #2400, #2350,#2300, #2200, #1000, #980, #970, #960, #950, #900, #850, MCF88, #650,MA600, MA7, MA8, MA11, MA100, MA220, IL30B, IL31B, IL7B, IL11B, IL52B,#4000, #4010, #55, #52, #50, #47, #45, #44, #40, #33, #32, #30, #20,#10, #5, CF9, #3050, #3150, #3250, #3750, #3950, DIABLACK A, DIABLACKN220M, DIABLACK N234, DIABLACK I, DIABLACK LI, DIABLACK II, DIABLACKN339, DIABLACK SH, DIABLACK SHA, DIABLACK LH, DIABLACK H, DIABLACK HA,DIABLACK SF, DIABLACK N550M, DIABLACK E, DIABLACK G, DIABLACK R,DIABLACK N760M, and DIABLACK LP manufactured by Mitsubishi ChemicalCorporation; Carbon Black Thermax N990, N991, N907, N908, N990, N991,and N908 manufactured by Cancarb; Carbon black Asahi #80, Asahi #70,Asahi #70L, Asahi F-200, Asahi #66, Asahi #66HN, Asahi #60H, Asahi #60U,Asahi #60, Asahi #55, Asahi #50H, Asahi #51, Asahi #50U, Asahi #50,Asahi #35, Asahi #15, and Asahi Thermal manufactured by Asahi CarbonCo., Ltd.; and Carbon Black COLOR BLACK FW200, COLOR BLACK FW2, COLORBLACK FW2V, COLOR BLACK FW1, COLOR BLACK FW18, COLOR BLACK S170, COLORBLACK S160, SPECIAL BLACK 6, SPECIAL BLACK 5, SPECIAL BLACK 4, SPECIALBLACK 4A, PRINTEX U, PRINTEX V, PRINTEX 140U, and PRINTEX 140Vmanufactured by Degussa.

The carbon black might preferably have insulating properties.

The carbon black having insulating properties is carbon black thatexhibits insulating properties when volume resistivity as a powder ismeasured by the method below. These insulating properties are based onan organic compound present on the surface of carbon black particles,such as an organic material adsorbing on, covering, or chemicallybonding (grafting) to the surface of carbon black particles.

That is, a coating liquid is prepared by dispersing carbon black inpropylene glycol monomethyl ether acetate at a ratio by weight of 20:80relative to a copolymer (weight-average molecular weight 30,000) ofbenzyl methacrylate and methacrylic acid with a molar ratio of 70:30,and applied to a chromium substrate with a thickness of 1.1 mm anddimensions of 10 cm×10 cm so as to give a coating with a dry filmthickness of 3 μm, the coating thus obtained is heated on a hot plate at220° C. for about 5 minutes, and a volume resistivity value is measuredby applying a voltage using a Hiresta-UP (MCP-HT450) manufactured byMitsubishi Chemical Corporation, which is a high resistivity meter inaccordance with JIS K6911, under an environment of 23° C. and a relativehumidity of 65%. It is preferable to use carbon black having a volumeresistivity value of at least 10⁵ Ω·cm, more preferably at least 10⁶Ω·cm, and particularly preferably at least 10⁷ Ω·cm.

As the above-mentioned carbon black, resin-coated carbon black disclosedin, for example, JP-A-11-60988, JP-A-11-60989, JP-A-10-330643,JP-A-11-80583, JP-A-11-80584, JP-A-9-124969, and JP-A-9-95625 may beused.

With regard to the average particle size (average primary particle size)of the black color material that is used in combination with titaniumblack, from the viewpoint of the occurrence of foreign matter and fromthe viewpoint of the influence on yield in the production of an imagesensor, the average primary particle size is preferably small. Theaverage primary particle size is preferably 10 to 100 nm, morepreferably 10 to 50 nm, and yet more preferably 10 to 30 nm.

The average particle size may be measured by coating an appropriatesubstrate with the black color material and examining with a scanningelectron microscope.

The content of titanium black in the photosensitive resin composition isnot particularly limited, but the average transmittance of a resultinglight-shielding color filter in the visible region to IR region (400 to1,600 nm) is preferably no greater than 1%. It is preferable that anoptical density of at least 2.0 is obtained at substantially the samefilm thickness as that of an RGB, etc. color separation filter.

The amount of titanium black combined in the photosensitive resincomposition of the present invention is preferably 10 to 60 wt % (alsocalled ‘mass %’) of the total solids content of the photosensitive resincomposition, and more preferably 20 to 40 wt %. The total solids contentof the photosensitive resin composition means the total amount of allthe components other than the organic solvent (E).

When titanium black is used in combination with another black colormaterial, the ratio by weight of titanium black:other black colormaterial is preferably 95:5 to 60:40, more preferably 95:5 to 70:30, andyet more preferably 90:10 to 80:20. When a plurality of said other blackcolor materials are used in combination, the total weight thereof ispreferably in the above-mentioned range.

It is preferable to set the ratio by weight of titanium black and theother black color material in the above-mentioned range since thedispersibility in the photosensitive resin composition becomes good, andan even and stable coating can be formed.

Furthermore, dispersion of the above-mentioned titanium black or carbonblack may employ a dispersant having an acid value/amine value, andspecific examples thereof include Solsperse 24000 and Solsperse 33500manufactured by Avecia and DISPER BYK-161 manufactured by BYK-ChemieJapan. ‘Having an acid value/amine value’ referred to here meanscomprising a group having an acid value, comprising a group having anamine value, or having both thereof.

Furthermore, as another dispersant, a homopolymer or a copolymerobtained by polymerization of a monomer such as (meth)acrylic acid, a(meth)acrylic acid ester, (meth)acrylamide or a derivative thereof, orstyrene or a derivative thereof may be used.

Examples of the monomer include styrene-based monomers such as styrene,o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene,p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene,m-chlorostyrene, and p-chlorostyrene; (meth)acrylic acid-based monomerssuch as acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate,n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, stearyl acrylate,2-ethylhexyl acrylate, hydroxyethyl acrylate, hydroxypropyl acrylate,methacrylic acid, methyl methacrylate, ethyl methacrylate, propylmethacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octylmethacrylate, dodecyl methacrylate, benzyl methacrylate, 2-ethylhexylmethacrylate, stearyl methacrylate, hydroxyethyl methacrylate, andhydroxypropyl methacrylate, ethylene, propylene, butylene, vinylchloride, vinyl acetate, acrylonitrile, acrylamide, methacrylamide, andN-vinylpyrrolidone.

Examples of homopolymers or copolymers include homopolymers orcopolymers of various types of monomers described above. Among them,(meth)acrylic acid ester-based polymers are preferable.

Furthermore, as another material that can be used for dispersion, aresin such as a polyurethane or a polyimide, or a siloxane-based polymerdescribed in JP-A-2002-241616 or JP-A-2002-234995 may be used.

The molecular weight of a resin used as a dispersant is not limited aslong as dispersibility can be guaranteed, but from the viewpoint ofdispersibility, the weight-average molecular weight is preferably 500 to200,000, more preferably 800 to 50,000, and yet more preferably 1,000 to30,000.

As a dispersion medium for dispersing a black color material such as thetitanium black or carbon black, as long as it can function as adispersion solvent, various types of water-soluble or water-insolublemedia may be used and, for example, alcohols such as methyl alcohol,ethyl alcohol, isopropyl alcohol, butyl alcohol, and allyl alcohol;glycols and derivatives thereof such as ethylene glycol, propyleneglycol, propylene glycol monomethyl ether, diethylene glycol,polyethylene glycol, polypropylene glycol, diethylene glycol monoethylether, polypropylene glycol monoethyl ether, polyethylene glycolmonoallyl ether, and polypropylene glycol monoallyl ether; glycerols andderivatives thereof such as glycerol, glycerol monoethyl ether, andglycerol monoallyl ether; ethers such as tetrahydrofuran and dioxane;ketones such as methyl ethyl ketone and methyl isobutyl ketone;hydrocarbons such as liquid paraffin, decane, decene, methylnaphthalene,decalin, kerosene, diphenylmethane, toluene, dimethylbenzene,ethylbenzene, diethylbenzene, propylbenzene, cyclohexane, and partiallyhydrogenated triphenyl, silicone oils such as polydimethylsiloxane,partially octyl-substituted polydimethylsiloxane, partiallyphenyl-substituted polydimethylsiloxane, and fluorosilicone oil,halohydrocarbons such as chlorobenzene, dichlorobenzene, bromobenzene,chlorodiphenyl, and chlorodiphenylmethane, fluorides such as DAIFLOIL(Daikin Industries Ltd.) and DEMNUM (Daikin Industries Ltd.), estercompounds such as ethyl benzoate, octyl benzoate, dioctyl phthalate,trioctyl trimellitate, dibutyl sebacate, ethyl(meth)acrylate,butyl(meth)acrylate, dodecyl(meth)acrylate, ethyl acetate, butylacetate, and propylene glycol monomethyl ether acetate, and amide-basedsolvents such as N,N-dimethylacrylamide, N,N-dimethylacetamide, andN-methylpyrrolidone may be selected as appropriate and used singly or ina combination of a plurality thereof.

When preparing a dispersion of a black color material such as titaniumblack in the present invention, relative to 100 parts by weight of blackcolor material, 5 to 200 parts by weight of polymer component ispreferably added, and more preferably 10 to 100 parts by weight.

When the polymer component is at least 5 parts by weight, the surfaceproperties of the black color material can be maintained well, and whenthe polymer component is no greater than 200 parts by weight, propertiesintrinsically required for the black color material such aslight-shielding properties and coloration properties can be improved.

The photosensitive resin composition of the present invention maycomprise, in addition to the above-mentioned black color material, aknown colorant such as a red, blue, green, yellow, cyan, magenta,violet, orange, etc. pigment or dye for the purpose of controllinglight-shielding properties at a desired wavelength.

With regard to the colorant, other than the black color material, usedin combination (combined colorant), relative to a sum total of 100 partsby weight of the black color material, including titanium black, and thecombined colorant, the combined colorant is preferably used in a rangeof 2 to 50 parts by weight, more preferably 2 to 30 parts by weight, andmost preferably 2 to 10 parts by weight.

(B) Polymerizable Compound

The photosensitive resin composition of the present invention comprisesa polymerizable compound. This polymerizable compound is preferably acompound that is addition-polymerized by the action of aphotopolymerization initiator. It is preferable to use as thepolymerizable compound an ethylenically unsaturated compound having atleast one ethylenically unsaturated bond per molecule, and morepreferable a polyfunctional ethylenically unsaturated compound havingtwo or more terminal ethylenically unsaturated bonds.

Such a group of compounds is widely known in the present industrialfield, and they may be used in the present invention without anyparticular restriction. They have a chemical configuration of, forexample, monomer, dimer, trimer, oligomer, or a mixture thereof.

The polymerizable compound preferably has a molecular weight of 70 to2,000, and more preferably 100 to 1,000.

Examples of the monomer include unsaturated carboxylic acids (e.g.acrylic acid, methacrylic acid, itaconic acid, crotonic acid,isocrotonic acid, maleic acid, etc.), esters thereof, and amidesthereof, and an ester of an unsaturated carboxylic acid and an aliphaticpolyhydric alcohol compound or an amide of an unsaturated carboxylicacid and an aliphatic polyamine compound are preferably used.Furthermore, an addition reaction product of an unsaturated carboxylicacid ester or amide having a nucleophilic substituent such as a hydroxygroup, an amino group, or a mercapto group with a monofunctional orpolyfunctional isocyanate or epoxy, a dehydration-condensation reactionproduct with a monofunctional or polyfunctional carboxylic acid, etc.may also be used suitably. Furthermore, an addition reaction product ofan unsaturated carboxylic acid ester or amide having an electrophilicsubstituent such as an isocyanate group or an epoxy group with amonofunctional or polyfunctional alcohol, amine, or thiol, and asubstitution reaction product of an unsaturated carboxylic acid ester oramide having a leaving substituent such as a halogen group or a tosyloxygroup with a monofunctional or polyfunctional alcohol, amine, or thiolare also suitable. Furthermore, as other examples, a group of compoundsin which the above-mentioned unsaturated carboxylic acid is replaced byan unsaturated phosphonic acid, styrene, vinyl ether, etc. may also beused.

Specific examples of ester monomers of an aliphatic polyhydric alcoholcompound and an unsaturated carboxylic acid include acrylic acid esterssuch as ethylene glycol diacrylate, triethylene glycol diacrylate,1,3-butanediol diacrylate, tetramethylene glycol diacrylate, propyleneglycol diacrylate, neopentyl glycol diacrylate, trimethylolpropanetriacrylate, trimethylolpropane tri(acryloyloxypropyl)ether,trimethylolethane triacrylate, hexanediol diacrylate,1,4-cyclohexanediol diacrylate, tetraethylene glycol diacrylate,pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritoltetraacrylate, dipentaerythritol diacrylate, dipentaerythritolhexaacrylate, sorbitol triacrylate, sorbitol tetraacrylate, sorbitolpentaacrylate, sorbitol hexaacrylate, tri(acryloyloxyethyl)isocyanurate, a polyester acrylate oligomer, and an ethyleneoxide(EO)-modified isocyanurate triacrylate.

Examples of methacrylic acid esters include tetramethylene glycoldimethacrylate, triethylene glycol dimethacrylate, neopentyl glycoldimethacrylate, trimethylolpropane trimethacrylate, trimethylolethanetrimethacrylate, ethylene glycol dimethacrylate, 1,3-butanedioldimethacrylate, hexanediol dimethacrylate, pentaerythritoldimethacrylate, pentaerythritol trimethacrylate, pentaerythritoltetramethacrylate, dipentaerythritol dimethacrylate, dipentaerythritolhexamethacrylate, sorbitol trimethacrylate, sorbitol tetramethacrylate,bis[p-(3-methacryloxy-2-hydroxypropoxy)phenyl]dimethylmethane, andbis[p-(methacryloxyethoxy)phenyl]dimethylmethane.

Examples of itaconic acid esters include ethylene glycol diitaconate,propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanedioldiitaconate, tetramethylene glycol diitaconate, pentaerythritoldiitaconate, and sorbitol tetraitaconate.

Examples of crotonic acid esters include ethylene glycol dicrotonate,tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, andsorbitol tetradicrotonate.

Examples of isocrotonic acid esters include ethylene glycoldiisocrotonate, pentaerythritol diisocrotonate, and sorbitoltetraisocrotonate.

Examples of maleic acid esters include ethylene glycol dimaleate,triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitoltetramaleate.

As examples of other esters, aliphatic alcohol-based esters described inJP-B-51-47334 (JP-B denotes a Japanese examined patent applicationpublication) and JP-A-57-196231, those having an aromatic skeletondescribed in JP-A-59-5240, JP-A-59-5241, and JP-A-2-226149, those havingan amino group described in JP-A-1-165613, etc. may also be usedsuitably. Moreover, the above-mentioned ester monomers may be used as amixture.

Furthermore, specific examples of amide monomers of an aliphaticpolyamine compound and an unsaturated carboxylic acid includemethylenebisacrylamide, methylenebismethacrylamide,1,6-hexamethylenebisacrylamide, 1,6-hexamethylenebismethacrylamide,diethylenetriaminetrisacrylamide, xylylenebisacrylamide, andxylylenebismethacrylamide.

Preferred examples of other amide-based monomers include those having acyclohexylene structure described in JP-B-54-21726.

Furthermore, a urethane-based addition-polymerizable compound producedby an addition reaction of an isocyanate and a hydroxy group is alsosuitable, and specific examples thereof include a vinylurethane compoundcontaining two or more polymerizable vinyl groups per molecule in whicha hydroxy group-containing vinyl monomer represented by Formula (A)below is added to a polyisocyanate compound having two or moreisocyanate groups per molecule described in JP-B-48-41708.CH₂═C(R⁴)COOCH₂CH(R⁵)OH  (A)(In Formula (A), R⁴ and R⁵ independently denote H or CH₃.)

Furthermore, urethane acrylates described in JP-A-51-37193,JP-B-2-32293, and JP-B-2-16765, and urethane compounds having anethylene oxide-based skeleton described in JP-B-5849860, JP-B-56-17654,JP-B-62-39417, JP-B-62-39418 are also suitable. Furthermore, by use ofan addition-polymerizable compound having an amino structure or asulfide structure in the molecule described in JP-A-63-277653,JP-A-63-260909, and JP-A-1-105238, a photosensitive resin compositionhaving very good photosensitive speed can be obtained.

Other examples include polyester acrylates such as those described inJP-A-48-64183, JP-B-49-43191, and JP-B-52-30490, and polyfunctionalacrylates and methacrylates such as epoxy acrylates formed by a reactionof an epoxy resin and (meth)acrylic acid. Examples also include specificunsaturated compounds described in JP-B-4643946, JP-B-1-40337, andJP-B-1-40336, and vinylphosphonic acid-based compounds described inJP-A-2-25493. In some cases, perfluoroalkyl group-containing structuresdescribed in JP-A-61-22048 are suitably used. Moreover, those describedas photocuring monomers or oligomers in the Journal of the AdhesionSociety of Japan, Vol. 20, No. 7, pp. 300 to 308 (1984) may also beused.

With regard to these polymerizable compounds, the structure thereof anddetails of an application method such as use thereof on their own or incombination and the amount thereof added may be freely set according tothe eventual performance design of a photosensitive resin composition.For example, selection is carried out from the following viewpoints.

From the viewpoint of sensitivity, a structure having a largeunsaturated group content per molecule is preferable, and in many casesdi- or higher-functionality is preferable. Furthermore, in order toincrease the strength of a cured coating, tri- or higher-functionalityis better, and it is also effective to adjust both sensitivity andstrength by using in combination different functionality/differentpolymerizable groups (e.g. an acrylic acid ester, a methacrylic acidester, a styrene-based compound, a vinyl ether-based compound).

Furthermore, selection and application methods of the polymerizablecompound are important factors for compatibility and dispersibility withother components (e.g. a photopolymerization initiator, titanium black,resin, etc.) contained in the photosensitive resin composition and, forexample, the compatibility can be improved by the use of a low puritycompound or the use of two or more types in combination. Moreover, inorder to improve adhesion to a hard surface such as a substrate, aspecific structure can be selected.

The content of the polymerizable compound (total content in the case oftwo or more types) in the total solids content of the photosensitiveresin composition of the present invention is not particularly limited,but from the viewpoint of obtaining the effects of the present inventioneffectively, it is preferably 10 to 80 wt %, more preferably 15 to 75 wt%, and particularly preferably 20 to 60 wt %.

When two or more types of polymerizable compounds are used incombination, it is preferable to use in combination two or more types ofethylenically unsaturated compounds having different numbers ofethylenically unsaturated groups (functionality) present per molecule.

In the present invention, it is more preferable to use in combinationethylenically unsaturated compounds having different functionalityselected from di- to hexa-functional, and it is yet more preferable touse in combination two types selected from tetra- to hexa-functional(meth)acrylic acid esters that are full (meth)acrylic acid esters ofaliphatic polyols.

(C) Photopolymerization Initiator

The photosensitive resin composition of the present invention comprises(C) a photopolymerization initiator.

Furthermore, the photosensitive resin composition of the presentinvention comprises two or more types of photopolymerization initiators(C) and, moreover, at least one type of photopolymerization initiator(C) is an oxime-based photopolymerization initiator.

The photopolymerization initiator is not particularly limited as long asit can photopolymerize the above-mentioned polymerizable compound, butit is preferably selected from the viewpoint of properties, initiationefficiency, absorption wavelength, availability, cost, etc.

Furthermore, as a photopolymerization initiator used in thephotosensitive resin composition of the present invention, a compoundthat does not have a halogen atom is preferable and, moreover, aninitiator having high sensitivity toward i rays is preferable; examplesthereof include lophine dimer and an oxime-based compound. Furthermore,as the oxime-based compound, an oxime ester-based compound ispreferable.

Moreover, the photopolymerization initiator preferably comprises atleast two types of oxime-based photopolymerization initiators or atleast one type of oxime-based photopolymerization initiator and at leastone type of halomethyl-s-triazine compound, and more preferablycomprises two or more types of oxime-based photopolymerizationinitiators.

The photopolymerization initiator that can be used in the presentinvention is a compound that generates a polymerization initiatingspecies by absorbing actinic radiation (light). Examples of the actinicradiation include γ rays, β rays, an electron beam, UV rays, visiblelight, and IR rays.

As the oxime-based photopolymerization initiator, a compound representedby Formula (1) below can be cited. In addition, the oxime compound inthe present invention may be an oxime compound in which the N—O bond ofthe oxime is in the (E) form or an oxime compound in which the N—O bondof the oxime is in the (Z) form, or may be a mixture of the (E) form andthe (Z) form.

(In Formula (1), R, A, and B independently denote a monovalentsubstituent.)

The monovalent substituent denoted by R is preferably a monovalentnon-metallic atomic group.

Examples of the monovalent non-metallic atomic group include an alkylgroup, an aryl group, an alkenyl group, an alkynyl group, analkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group, anarylsulfonyl group, an acyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a phosphinoyl group, a heterocyclic group, analkylthiocarbonyl group, an arylthiocarbonyl group, adialkylaminocarbonyl group, and a dialkylaminothiocarbonyl group. Thesegroups may have one or more substituents. The substituent may further besubstituted by another substituent.

Examples of the substituent include halogen atoms such as a fluorineatom, a chlorine atom, a bromine atom, and an iodine atom, alkoxy groupssuch as a methoxy group, an ethoxy group, and a tert-butoxy group,aryloxy groups such as a phenoxy group and a p-tolyloxy group,alkoxycarbonyl and aryloxycarbonyl groups such as a methoxycarbonylgroup, a butoxycarbonyl group, and a phenoxycarbonyl group, acyloxygroups such as an acetoxy group, a propionyloxy group, and a benzoyloxygroup, acyl groups such as an acetyl group, a benzoyl group, anisobutyryl group, an acryloyl group, a methacryloyl group, and amethoxalyl group, alkylsulfanyl groups such as a methylsulfanyl groupand a tert-butylsulfanyl group, arylsulfanyl groups such as aphenylsulfanyl group and a p-tolylsulfanyl group, alkylamino groups suchas a methylamino group and a cyclohexylamino group, dialkylamino groupssuch as a dimethylamino group, a diethylamino group, a morpholino group,and a piperidino group, arylamino groups such as a phenylamino group anda p-tolylamino group, alkyl groups such as a methyl group, an ethylgroup, a tert-butyl group, and a dodecyl group, and aryl groups such asa phenyl group, a p-tolyl group, a xylyl group, a cumenyl group, anaphthyl group, an anthryl group, and a phenanthryl group, as well as ahydroxy group, a carboxy group, a formyl group, a mercapto group, asulfo group, a mesyl group, a p-toluenesulfonyl group, an amino group, anitro group, a cyano group, a trifluoromethyl group, a trichloromethylgroup, a trimethylsilyl group, a phosphono group, a trimethylammoniumgroup, a dimethylsulfonium group, and a triphenylphenacylsulfoniumgroup.

The alkyl group is preferably an alkyl group having 1 to 30 carbons, andspecific examples thereof include a methyl group, an ethyl group, apropyl group, a butyl group, a hexyl group, an octyl group, a decylgroup, a dodecyl group, an octadecyl group, an isopropyl group, anisobutyl group, a sec-butyl group, a t-butyl group, a 1-ethylpentylgroup, a cyclopentyl group, a cyclohexyl group, a trifluoromethyl group,a 2-ethylhexyl group, a phenacyl group, a 1-naphthoylmethyl group, a2-naphthoylmethyl group, a 4-methylsulfanylphenacyl group, a4-phenylsulfanylphenacyl group, a 4-dimethylaminophenacyl group, a4-cyanophenacyl group, a 4-methylphenacyl group, a 2-methylphenacylgroup, a 3-fluorophenacyl group, a 3-trifluoromethylphenacyl group, anda 3-nitrophenacyl group.

The aryl group is preferably an aryl group having 6 to 30 carbons, andspecific examples thereof include a phenyl group, a biphenyl group, a1-naphthyl group, a 2-naphthyl group, a 9-anthryl group, a 9-phenanthrylgroup, a 1-pyrenyl group, a 5-naphthacenyl group, a 1-indenyl group, a2-azulenyl group, a 9-fluorenyl group, a terphenyl group, a quaterphenylgroup, o-, m-, and p-tolyl groups, a xylyl group, o-, m-, and p-cumenylgroups, a mesityl group, a pentalenyl group, a binaphthalenyl group, aternaphthalenyl group, a quaternaphthalenyl group, a heptalenyl group, abiphenylenyl group, an indacenyl group, a fluoranthenyl group, anacenaphthylenyl group, an aceanthrylenyl group, a phenalenyl group, afluorenyl group, an anthryl group, a bianthracenyl group, ateranthracenyl group, a quateranthracenyl group, an anthraquinolylgroup, a phenanthryl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a pleiadenyl group, a picenylgroup, a perylenyl group, a pentaphenyl group, a pentacenyl group, atetraphenylenyl group, a hexaphenyl group, a hexacenyl group, arubicenyl group, a coronenyl group, a trinaphthylenyl group, aheptaphenyl group, a heptacenyl group, a pyranthrenyl group, and anovalenyl group.

The alkenyl group is preferably an alkenyl group having 2 to 10 carbons,and specific examples thereof include a vinyl group, an allyl group, anda styryl group.

The alkynyl group is preferably an alkynyl group having 2 to 10 carbons,and specific examples thereof include an ethynyl group, a propynylgroup, and a propargyl group.

The alkylsulfinyl group is preferably an alkylsulfinyl group having 1 to20 carbons, and specific examples thereof include a methylsulfinylgroup, an ethylsulfinyl group, a propylsulfinyl group, anisopropylsulfinyl group, a butylsulfinyl group, a hexylsulfinyl group, acyclohexylsulfinyl group, an octylsulfinyl group, a 2-ethylhexylsulfinylgroup, a decanoylsulfinyl group, a dodecanoylsulfinyl group, anoctadecanoylsulfinyl group, a cyanomethylsulfinyl group, and amethoxymethylsulfinyl group.

The arylsulfinyl group is preferably an arylsulfinyl group having 6 to30 carbons, and specific examples thereof include a phenylsulfinylgroup, a 1-naphthylsulfinyl group, a 2-naphthylsulfinyl group, a2-chlorophenylsulfinyl group, a 2-methylphenylsulfinyl group, a2-methoxyphenylsulfinyl group, a 2-butoxyphenylsulfinyl group, a3-chlorophenylsulfinyl group, a 3-trifluoromethylphenylsulfinyl group, a3-cyanophenylsulfinyl group, a 3-nitrophenylsulfinyl group, a4-fluorophenylsulfinyl group, a 4-cyanophenylsulfinyl group, a4-methoxyphenylsulfinyl group, a 4-methylsulfanylphenylsulfinyl group, a4-phenylsulfanylphenylsulfinyl group, and a4-dimethylaminophenylsulfinyl group.

The alkylsulfonyl group is preferably an alkylsulfonyl group having 1 to20 carbons, and specific examples thereof include a methylsulfonylgroup, an ethylsulfonyl group, a propylsulfonyl group, anisopropylsulfonyl group, a butylsulfonyl group, a hexylsulfonyl group, acyclohexylsulfonyl group, an octylsulfonyl group, a 2-ethylhexylsulfonylgroup, a decanoylsulfonyl group, a dodecanoylsulfonyl group, anoctadecanoylsulfonyl group, a cyanomethylsulfonyl group, amethoxymethylsulfonyl group, and a perfluoroalkylsulfonyl group.

The arylsulfonyl group is preferably an arylsulfonyl group having 6 to30 carbons, and specific examples thereof include a phenylsulfonylgroup, a 1-naphthylsulfonyl group, a 2-naphthylsulfonyl group, a2-chlorophenylsulfonyl group, a 2-methylphenylsulfonyl group, a2-methoxyphenylsulfonyl group, a 2-butoxyphenylsulfonyl group, a3-chlorophenylsulfonyl group, a 3-trifluoromethylphenylsulfonyl group, a3-cyanophenylsulfonyl group, a 3-nitrophenylsulfonyl group, a4-fluorophenylsulfonyl group, a 4-cyanophenylsulfonyl group, a4-methoxyphenylsulfonyl group, a 4-methylsulfanylphenylsulfonyl group, a4-phenylsulfanylphenylsulfonyl group, and a4-dimethylaminophenylsulfonyl group.

The acyl group is preferably an acyl group having 2 to 20 carbons, andspecific examples thereof include an acetyl group, a propanoyl group, abutanoyl group, a trifluoroacetyl group, a pentanoyl group, a benzoylgroup, a 1-naphthoyl group, a 2-naphthoyl group, a4-methylsulfanylbenzoyl group, a 4-phenylsulfanylbenzoyl group, a4-dimethylaminobenzoyl group, a 4-diethylaminobenzoyl group, a2-chlorobenzoyl group, a 2-methylbenzoyl group, a 2-methoxybenzoylgroup, a 2-butoxybenzoyl group, a 3-chlorobenzoyl group, a3-trifluoromethylbenzoyl group, a 3-cyanobenzoyl group, a 3-nitrobenzoylgroup, a 4-fluorobenzoyl group, a 4-cyanobenzoyl group, and a4-methoxybenzoyl group.

The alkoxycarbonyl group is preferably an alkoxycarbonyl group having 2to 20 carbons, and specific examples thereof include a methoxycarbonylgroup, an ethoxycarbonyl group, a propoxycarbonyl group, abutoxycarbonyl group, a hexyloxycarbonyl group, an octyloxycarbonylgroup, a decyloxycarbonyl group, an octadecyloxycarbonyl group, and atrifluoromethyloxycarbonyl group.

Specific examples of the aryloxycarbonyl group include a phenoxycarbonylgroup, a 1-naphthyloxycarbonyl group, a 2-naphthyloxycarbonyl group, a4-methylsulfanylphenyloxycarbonyl group, a4-phenylsulfanylphenyloxycarbonyl group, a4-dimethylaminophenyloxycarbonyl group, a4-diethylaminophenyloxycarbonyl group, a 2-chlorophenyloxycarbonylgroup, a 2-methylphenyloxycarbonyl group, a 2-methoxyphenyloxycarbonylgroup, a 2-butoxyphenyloxycarbonyl group, a 3-chlorophenyloxycarbonylgroup, a 3-trifluoromethylphenyloxycarbonyl group, a3-cyanophenyloxycarbonyl group, a 3-nitrophenyloxycarbonyl group, a4-fluorophenyloxycarbonyl group, a 4-cyanophenyloxycarbonyl group, and a4-methoxyphenyloxycarbonyl group.

The phosphinoyl group is preferably a phosphinoyl group having 2 to 50carbons, and specific examples thereof include a dimethylphosphinoylgroup, a diethylphosphinoyl group, a dipropylphosphinoyl group, adiphenylphosphinoyl group, a dimethoxyphosphinoyl group, adiethoxyphosphinoyl group, a dibenzoylphosphinoyl group, and abis(2,4,6-trimethylphenyl)phosphinoyl group.

The heterocyclic group is preferably a nitrogen atom-, oxygen atom-,sulfur atom-, or phosphorus atom-containing aromatic or aliphaticheterocycle.

Specific examples thereof include a thienyl group, a benzo[b]thienylgroup, a naphtho[2,3-b]thienyl group, a thianthrenyl group, a furylgroup, a pyranyl group, an isobenzofuranyl group, a chromenyl group, axanthenyl group, a phenoxathiinyl group, a 2H-pyrrolyl group, a pyrrolylgroup, an imidazolyl group, a pyrazolyl group, a pyridyl group, apyrazinyl group, a pyrimidinyl group, a pyridazinyl group, anindolizinyl group, an isoindolyl group, a 3H-indolyl group, an indolylgroup, a 1H-indazolyl group, a purinyl group, a 4H-quinolidinyl group,an isoquinolyl group, a quinolyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a pteridinyl group, a 4aH-carbazolyl group, acarbazolyl group, a β-carbolinyl group, a phenanthridinyl group, anacridinyl group, a perimidinyl group, a phenanthrolinyl group, aphenazinyl group, a phenarsazinyl group, an isothiazolyl group, aphenothiazinyl group, an isoxazolyl group, a furazanyl group, aphenoxazinyl group, an isochromanyl group, a chromanyl group, apyrrolidinyl group, a pyrrolinyl group, an imidazolidinyl group, animidazolinyl group, a pyrazolidinyl group, a pyrazolinyl group, apiperidyl group, a piperazinyl group, an indolinyl group, anisoindolinyl group, a quinuclidinyl group, a morpholinyl group, and athioxanthryl group.

Specific examples of the alkylthiocarbonyl group include amethylthiocarbonyl group, a propylthiocarbonyl group, abutylthiocarbonyl group, a hexylthiocarbonyl group, an octylthiocarbonylgroup, a decylthiocarbonyl group, an octadecylthiocarbonyl group, and atrifluoromethylthiocarbonyl group.

Specific examples of the arylthiocarbonyl group include a1-naphthylthiocarbonyl group, a 2-naphthylthiocarbonyl group, a4-methylsulfanylphenylthiocarbonyl group, a4-phenylsulfanylphenylthiocarbonyl group, a4-dimethylaminophenylthiocarbonyl group, a4-diethylaminophenylthiocarbonyl group, a 2-chlorophenylthiocarbonylgroup, a 2-methylphenylthiocarbonyl group, a 2-methoxyphenylthiocarbonylgroup, a 2-butoxyphenylthiocarbonyl group, a 3-chlorophenylthiocarbonylgroup, a 3-trifluoromethylphenylthiocarbonyl group, a3-cyanophenylthiocarbonyl group, a 3-nitrophenylthiocarbonyl group, a4-fluorophenylthiocarbonyl group, a 4-cyanophenylthiocarbonyl group, anda 4-methoxyphenylthiocarbonyl group.

Specific examples of the dialkylaminocarbonyl group include adimethylaminocarbonyl group, a diethylaminocarbonyl group, adipropylaminocarbonyl group, and a dibutylaminocarbonyl group.

Specific examples of the dialkylaminothiocarbonyl group include adimethylaminothiocarbonyl group, a dipropylaminothiocarbonyl group, anda dibutylaminothiocarbonyl group.

Among them, from the viewpoint of high sensitivity, R is more preferablyan acyl group, and specific preferred examples thereof include an acetylgroup, a propanoyl group, a benzoyl group, and a toluoyl group.

The monovalent substituent denoted by A above is preferably an alkylgroup, an aryl group, a heterocyclic group, or a sulfur atom-containinggroup, and more preferably an alkyl group or a sulfur atom-containinggroup. These groups may have one or more substituents. As thesubstituent, the above-mentioned substituents can be cited. Theabove-mentioned substituents may further be substituted by anothersubstituent.

A preferred range for the alkyl group, aryl group, and heterocyclicgroup denoted by A above is the same as the preferred range for thealkyl group, aryl group, and heterocyclic group denoted by R above.

Furthermore, the sulfur atom-containing group denoted by A above ispreferably -A¹-SAr. A¹ and Ar have the same meanings as those for A¹ andAr in Formula (2), which is described later, and preferred examples arealso the same.

The monovalent substituent denoted by B above is an aryl group, aheterocyclic group, an arylcarbonyl group, or a heterocyclic carbonylgroup. These groups may have one or more substituents. As thesubstituent, the above-mentioned substituents can be cited. Theabove-mentioned substituents may further be substituted by anothersubstituent.

Among them, as the monovalent substituent denoted by B, the structuresshown below are particularly preferable.

In the structures below, Y, X, and n have the same meanings as those ofY, X, and n in Formula (3), which is described later, and preferredexamples are also the same.

The oxime-based photopolymerization initiator preferably comprises2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,or a compound represented by Formula (1) above, more preferablycomprises 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,or a compound represented by Formula (2) below (hereinafter, also calleda ‘specific oxime compound’), and yet more preferably is2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,and/or a compound represented by Formula (2) below.

(In Formula (2), R and B independently denote a monovalent substituent,A¹ denotes a divalent organic group, and Ar denotes an aryl group.)

R and B in Formula (2) have the same meanings as those of R and B inFormula (1) above, and preferred ranges are also the same.

As the divalent organic group denoted by A¹ above, alkylene,cyclohexylene, and alkynylene groups having 1 to 12 carbon atoms can becited. Furthermore, these groups may have one or more substituents. Asthe substituent, the above-mentioned substituents can be cited. Theabove-mentioned substituents may further be substituted by anothersubstituent.

Among them, from the viewpoint of enhancing the sensitivity andsuppressing coloration due to thermal aging, A¹ is preferably anunsubstituted alkylene group, an alkyl group (e.g. methyl group, ethylgroup, tert-butyl group, dodecyl group)-substituted alkylene group, analkenyl group (e.g. vinyl group, allyl group)-substituted alkylenegroup, or an aryl group (e.g. phenyl group, p-tolyl group, xylyl group,cumenyl group, naphthyl group, anthryl group, phenanthryl group, styrylgroup)-substituted alkylene group.

The aryl group denoted by Ar is preferably an aryl group having 6 to 30carbons, and may have a substituent. As the substituent, theabove-mentioned substituents can be cited.

Specific examples thereof include a phenyl group, a biphenyl group, a1-naphthyl group, a 2-naphthyl group, a 9-anthryl group, a 9-phenanthrylgroup, a 1-pyrenyl group, a 5-naphthacenyl group, a 1-indenyl group, a2-azulenyl group, a 9-fluorenyl group, a terphenyl group, a quaterphenylgroup, o-, m-, and p-tolyl groups, a xylyl group, o-, m-, and p-cumenylgroups, a mesityl group, a pentalenyl group, a binaphthalenyl group, aternaphthalenyl group, a quaternaphthalenyl group, a heptalenyl group, abiphenylenyl group, an indacenyl group, a fluoranthenyl group, anacenaphthylenyl group, an aceanthrylenyl group, a phenalenyl group, afluorenyl group, an anthryl group, a bianthracenyl group, ateranthracenyl group, a quateranthracenyl group, an anthraquinolylgroup, a phenanthryl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a pleiadenyl group, a picenylgroup, a perylenyl group, a pentaphenyl group, a pentacenyl group, atetraphenylenyl group, a hexaphenyl group, a hexacenyl group, arubicenyl group, a coronenyl group, a trinaphthylenyl group, aheptaphenyl group, a heptacenyl group, a pyranthrenyl group, and anovalenyl group.

Among them, from the viewpoint of enhancing sensitivity and suppressingcoloration due to heating over time, a substituted or unsubstitutedphenyl group is preferable.

In Formula (2), from the viewpoint of sensitivity the structure of ‘SAr’formed by the Ar and the adjacent S is preferably a structure shownbelow. Me denotes a methyl group, and Et denotes an ethyl group.

The specific oxime compound in the present invention is preferably acompound represented by Formula (3) below.

(In Formula (3), R and X independently denote a monovalent substituent,A¹ and Y independently denote a divalent organic group, Ar denotes anaryl group, and n is an integer of 0 to 5.)

R, A¹, and Ar in Formula (3) have the same meanings as R in Formula (1)above and those of A¹ and Ar in Formula (2) above, and preferredexamples are also the same.

As the monovalent substituent denoted by X, an alkyl group, an arylgroup, an alkenyl group, an alkynyl group, an alkoxy group, an aryloxygroup, an acyloxy group, an alkylsulfanyl group, an arylsulfanyl group,an alkylsulfinyl group, an arylsulfinyl group, an alkylsulfonyl group,an arylsulfonyl group, an acyl group, an alkoxycarbonyl group, acarbamoyl group, a sulfamoyl group, an amino group, a phosphinoyl group,a heterocyclic group, and a halogen atom can be cited. These groups mayhave one or more substituents. As the substituent, the above-mentionedsubstituents can be cited as examples. The above-mentioned substituentmay further be substituted by another substituent.

The alkyl group, aryl group, alkenyl group, alkynyl group, alkylsulfinylgroup, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, acylgroup, alkoxycarbonyl group, aryloxycarbonyl group, phosphinoyl group,and heterocyclic group denoted by X above have the same meanings as thealkyl group, aryl group, alkenyl group, alkynyl group, alkylsulfinylgroup, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, acylgroup, alkoxycarbonyl group, aryloxycarbonyl group, phosphinoyl group,and heterocyclic group denoted by R in Formula (1) above, and preferredranges are also the same.

The alkoxy group is preferably an alkoxy group having 1 to 30 carbons,and specific examples thereof include a methoxy group, an ethoxy group,a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxygroup, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, anisopentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxygroup, a 2-ethylhexyloxy group, a decyloxy group, a dodecyloxy group, anoctadecyloxy group, an ethoxycarbonylmethyl group, a2-ethylhexyloxycarbonylmethyloxy group, an aminocarbonylmethyloxy group,an N,N-dibutylaminocarbonylmethyloxy group, anN-methylaminocarbonylmethyloxy group, an N-ethylaminocarbonylmethyloxygroup, an N-octylaminocarbonylmethyloxy group, anN-methyl-N-benzylaminocarbonylmethyloxy group, a benzyloxy group, and acyanomethyloxy group.

The aryloxy group is preferably an aryloxy group having 6 to 30 carbons,and specific examples thereof include a phenyloxy group, a 1-naphthyloxygroup, a 2-naphthyloxy group, a 2-chlorophenyloxy group, a2-methylphenyloxy group, a 2-methoxyphenyloxy group, a 2-butoxyphenyloxygroup, a 3-chlorophenyloxy group, a 3-trifluoromethylphenyloxy group, a3-cyanophenyloxy group, a 3-nitrophenyloxy group, a 4-fluorophenyloxygroup, a 4-cyanophenyloxy group, a 4-methoxyphenyloxy group, a4-dimethylaminophenyloxy group, a 4-methylsulfanylphenyloxy group, and a4-phenylsulfanylphenyloxy group.

The acyloxy group is preferably an acyloxy group having 2 to 20 carbons,and specific examples thereof include an acetyloxy group, a propanoyloxygroup, a butanoyloxy group, a pentanoyloxy group, atrifluoromethylcarbonyloxy group, a benzoyloxy group, a1-naphthylcarbonyloxy group, and a 2-naphthylcarbonyloxy group.

The alkylsulfanyl group is preferably an alkylsulfanyl group having 1 to20 carbons, and specific examples thereof include a methylsulfanylgroup, an ethylsulfanyl group, a propylsulfanyl group, anisopropylsulfanyl group, a butylsulfanyl group, a hexylsulfanyl group, acyclohexylsulfanyl group, an octylsulfanyl group, a 2-ethylhexylsulfanylgroup, a decanoylsulfanyl group, a dodecanoylsulfanyl group, anoctadecanoylsulfanyl group, a cyanomethylsulfanyl group, and amethoxymethylsulfanyl group.

The arylsulfanyl group is preferably an arylsulfanyl group having 6 to30 carbons, and specific examples thereof include a phenylsulfanylgroup, a 1-naphthylsulfanyl group, a 2-naphthylsulfanyl group, a2-chlorophenylsulfanyl group, a 2-methylphenylsulfanyl group, a2-methoxyphenylsulfanyl group, a 2-butoxyphenylsulfanyl group, a3-chlorophenylsulfanyl group, a 3-trifluoromethylphenylsulfanyl group, a3-cyanophenylsulfanyl group, a 3-nitrophenylsulfanyl group, a4-fluorophenylsulfanyl group, a 4-cyanophenylsulfanyl group, a4-methoxyphenylsulfanyl group, a 4-methylsulfanylphenylsulfanyl group, a4-phenylsulfanylphenylsulfanyl group, and a4-dimethylaminophenylsulfanyl group.

The carbamoyl group is preferably a carbamoyl group having a total of 1to 30 carbons, and specific examples thereof include anN-methylcarbamoyl group, an N-ethylcarbamoyl group, an N-propylcarbamoylgroup, an N-butylcarbamoyl group, an N-hexylcarbamoyl group, anN-cyclohexylcarbamoyl group, an N-octylcarbamoyl group, anN-decylcarbamoyl group, an N-octadecylcarbamoyl group, anN-phenylcarbamoyl group, an N-2-methylphenylcarbamoyl group, anN-2-chlorophenylcarbamoyl group, an N-2-isopropoxyphenylcarbamoyl group,an N-2-(2-ethylhexyl)phenylcarbamoyl group, an N-3-chlorophenylcarbamoylgroup, an N-3-nitrophenylcarbamoyl group, an N-3-cyanophenylcarbamoylgroup, an N-4-methoxyphenylcarbamoyl group, an N-4-cyanophenylcarbamoylgroup, an N-4-methylsulfanylphenylcarbamoyl group, anN-4-phenylsulfanylphenylcarbamoyl group, an N-methyl-N-phenylcarbamoylgroup, an N,N-dimethylcarbamoyl group, an N,N-dibutylcarbamoyl group,and an N,N-diphenylcarbamoyl group.

The sulfamoyl group is preferably a sulfamoyl group having a total of 0to 30 carbons, and specific examples thereof include a sulfamoyl group,an N-alkylsulfamoyl group, an N-arylsulfamoyl group, anN,N-dialkylsulfamoyl group, an N,N-diarylsulfamoyl group, and anN-alkyl-N-arylsulfamoyl group. More specific preferred examples thereofinclude an N-methylsulfamoyl group, an N-ethylsulfamoyl group, anN-propylsulfamoyl group, an N-butylsulfamoyl group, an N-hexylsulfamoylgroup, an N-cyclohexylsulfamoyl group, an N-octylsulfamoyl group, anN-2-ethylhexylsulfamoyl group, an N-decylsulfamoyl group, anN-octadecylsulfamoyl group, an N-phenylsulfamoyl group, anN-2-methylphenylsulfamoyl group, an N-2-chlorophenylsulfamoyl group, anN-2-methoxyphenylsulfamoyl group, an N-2-isopropoxyphenylsulfamoylgroup, an N-3-chlorophenylsulfamoyl group, an N-3-nitrophenylsulfamoylgroup, an N-3-cyanophenylsulfamoyl group, an N-4-methoxyphenylsulfamoylgroup, an N-4-cyanophenylsulfamoyl group, anN-4-dimethylaminophenylsulfamoyl group, anN-4-methylsulfanylphenylsulfamoyl group, anN-4-phenylsulfanylphenylsulfamoyl group, an N-methyl-N-phenylsulfamoylgroup, an N,N-dimethylsulfamoyl group, an N,N-dibutylsulfamoyl group,and an N,N-diphenylsulfamoyl group.

The amino group is preferably an amino group having a total of 0 to 50carbons, and specific examples thereof include an amino group (—NH₂), anN-alkylamino group, an N-arylamino group, an N-acylamino group, anN-sulfonylamino group, an N,N-dialkylamino group, an N,N-diarylaminogroup, an N-alkyl-N-arylamino group, and an N,N-disulfonylamino group.More specific preferred examples thereof include an N-methylamino group,an N-ethylamino group, an N-propylamino group, an N-isopropylaminogroup, an N-butylamino group, an N-tert-butylamino group, anN-hexylamino group, an N-cyclohexylamino group, an N-octylamino group,an N-2-ethylhexylamino group, an N— decylamino group, anN-octadecylamino group, an N-benzylamino group, an N-phenylamino group,an N-2-methylphenylamino group, an N-2-chlorophenylamino group, anN-2-methoxyphenylamino group, an N-2-isopropoxyphenylamino group, anN-2-(2-ethylhexyl)phenylamino group, an N-3-chlorophenylamino group, anN-3-nitrophenylamino group, an N-3-cyanophenylamino group, anN-3-trifluoromethylphenylamino group, an N-4-methoxyphenylamino group,an N-4-cyanophenylamino group, an N-4-trifluoromethylphenylamino group,an N-4-methylsulfanylphenylamino group, an N-4-phenylsulfanylphenylaminogroup, an N-4-dimethylaminophenylamino group, an N-methyl-N-phenylaminogroup, an N,N-dimethylamino group, an N,N-diethylamino group, anN,N-dibutylamino group, an N,N-diphenylamino group, an N,N-diacetylaminogroup, an N,N-dibenzoylamino group, an N,N-(dibutylcarbonyl)amino group,an N,N-(dimethylsulfonyl)amino group, an N,N-(diethylsulfonyl)aminogroup, an N,N-(dibutylsulfonyl)amino group, anN,N-(diphenylsulfonyl)amino group, an N,N-(diphenylsulfonyl)amino group,a morpholino group, a 3,5-dimethylmorpholino group, and a carbazolegroup.

As the halogen atom, a fluorine atom, a chlorine atom, a bromine atom,and an iodine atom can be cited.

Among them, from the viewpoint of solvent solubility and improvement ofabsorption efficiency in a long wavelength region, X is preferably analkyl group, an aryl group, an alkenyl group, an alkynyl group, analkoxy group, an aryloxy group, an alkylsulfanyl group, an arylsulfanylgroup, or an amino group.

Furthermore, n in Formula (3) denotes an integer of 0 to 5, andpreferably an integer of 0 to 2.

As the divalent organic group denoted by Y above, the structures shownbelow can be cited. In the group shown below, ‘*’ denotes a bondingposition to a carbon atom adjacent to Y in Formula (3) above.

Among them, from the viewpoint of high sensitivity, the structures shownbelow are preferable.

The specific oxime compound in the present invention is preferably acompound represented by Formula (4) below.

(In Formula (4), R and X independently denote a monovalent substituent,A¹ denotes a divalent organic group, Ar denotes an aryl group, and n isan integer of 0 to 5.)

R, X, A¹, Ar, and n in Formula (4) have the same meanings as R inFormula (1) above, those of A¹ and Ar in Formula (2) above, and those ofX and n in Formula (3) above, and preferred examples are also the same.

Specific examples (K-1) to (K-88) of the specific oxime compound in thepresent invention are shown below, but the specific oxime compoundshould not be construed as being limited thereto.

(5)

—R^(A) —OR —R^(B) K-1

—CH₃ K-2

K-3

K-4

K-5

K-6

K-7

K-8

K-9

K-10

K-11

K-12

K-13

K-14

K-15

K-16

K-17

K-18

K-19

K-20

K-21

K-22

K-23

K-24

K-25

K-26

K-27

K-28

K-29

K-30

K-31

K-32

K-33

K-34

K-35

K-36

K-37

K-38

K-39

K-40

K-41

—OCH₃

K-42

K-43

K-44

K-45

K-46

K-47

K-48

K-49

K-50

K-51

K-52

K-53

K-54

K-55

K-56

K-57

K-58

K-59

K-60

K-61

—OCH₃

K-62

K-63

K-64

K-65

K-66

(6)

—R^(C) —OR —R^(D) K-67

K-68

K-69

K-70

K-71

K-72

K-73

K-74

K-75

K-76

K-77

K-78

K-79

K-80

K-81

K-82

K-83

K-84

—OCH₃

K-85

K-86

K-87

K-88

The specific oxime compound in the present invention preferably has amaximum absorption wavelength in a wavelength region of 350 nm to 500nm, more preferably has an absorption wavelength in a wavelength regionof 360 nm to 480 nm, and particularly preferably has a high absorbanceat 365 nm and 455 nm. In particular, the specific oxime compound hasabsorption in a longer wavelength region compared with a conventionaloxime-based compound, and when exposure is carried out using a lightsource at 365 nm or 405 nm, excellent sensitivity is exhibited.

From the viewpoint of sensitivity, the specific oxime compound in thepresent invention preferably has a molar extinction coefficient(L·mol⁻¹·cm⁻¹) at 365 nm or 405 nm of 10,000 to 300,000, more preferably15,000 to 300,000, and particularly preferably 20,000 to 200,000.

In the present invention, the molar extinction coefficient of a compoundmay be measured by a known method, and specifically it is preferable tocarry out measurement using, for example, ethyl acetate solvent at aconcentration of 0.01 g/L with a UV-visible spectrophotometer (Carry-5spectrophotometer manufactured by Varian).

The specific oxime compound in the present invention may be synthesizedby, for example, the method shown below, but it is not limited to thismethod.

Synthesis of Compound Represented by Formula (3)

Furthermore, examples of the photopolymerization initiator that can beused in the present invention include, in addition to an oxime-basedcompound, at least one active halogen compound selected from ahalomethyloxadiazole compound and a halomethyl-s-triazine compound, a3-aryl-substituted coumarin compound, lophine dimer, a benzophenonecompound, an acetophenone compound and a derivative thereof, and acyclopentadiene-benzene-iron complex and a salt thereof. Among them,other than an oxime-based compound, it is preferable to use ahalomethyl-s-triazine compound.

Examples of the halomethyloxadiazole compound include a2-halomethyl-5-vinyl-1,3,4-oxadiazole compound, etc. described inJP-B-57-6096, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole,2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole, and2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole.

Examples of the halomethyl-s-triazine compound include avinylhalomethyl-s-triazine compound described in JP-B-59-1281, a2-(naphtho-1-yl)-4,6-bishalomethyl-s-triazine compound described inJP-A-53-133428, and a 4-(p-aminophenyl)-2,6-dihalomethyl-s-triazinecompound.

Specific examples of the halomethyl-s-triazine compound include2,4-bis(trichloromethyl)-6-p-methoxystyryl-s-triazine,2,6-bis(trichloromethyl)-4-(3,4-methylenedioxyphenyl)-1,3,5-triazine,2,6-bis(trichloromethyl)-4-(4-methoxyphenyl)-1,3,5-triazine,2,4-bis(trichloromethyl)-6-(1-p-dimethylaminophenyl-1,3-butadienyl)-s-triazine,2-trichloromethyl-4-amino-6-p-methoxystyryl-s-triazine,2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-ethoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4-butoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-[4-(2-methoxyethyl)naphtho-1-yl]-4,6-bis(trichloromethyl)-s-triazine,

2-[4-(2-ethoxyethyl)naphtho-1-yl]-4,6-bis(trichloromethyl)-s-triazine,2-[4-(2-butoxyethyl)naphtho-1-yl]-4,6-bis(trichloromethyl)-s-triazine,2-(2-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(6-methoxy-5-methylnaphtho-2-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(6-methoxynaphtho-2-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(5-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(4,7-dimethoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,2-(6-ethoxynaphtho-2-yl)-4,6-bistrichloromethyl-s-triazine,2-(4,5-dimethoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine,

4-[p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-methyl-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-methyl-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-(p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-[p-N,N-di(phenyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-(p-N-chloroethylcarbonylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,

4-[p-N-(p-methoxyphenyl)carbonylaminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-bromo-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-chloro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-fluoro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-bromo-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-chloro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,

4-[o-fluoro-p-N,N-di(ethoxycarbonylmethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-bromo-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-chloro-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[o-fluoro-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-bromo-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-[m-chloro-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,

4-[m-fluoro-p-N,N-di(chloroethyl)aminophenyl]-2,6-di(trichloromethyl)-s-triazine,4-(m-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(m-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(m-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(o-bromo-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(o-chloro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,

4-(o-fluoro-p-N-ethoxycarbonylmethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(m-bromo-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(m-chloro-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(m-fluoro-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(o-bromo-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,4-(o-chloro-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine,and4-(o-fluoro-p-N-chloroethylaminophenyl)-2,6-di(trichloromethyl)-s-triazine.

In addition thereto, the TAZ series manufactured by Midori Kagaku Co.,Ltd. (e.g. TAZ-107, TAZ-110, TAZ-104, TAZ-109, TAZ-140, TAZ-204,TAZ-113, TAZ-123), the T series manufactured by PANCHIM (e.g. T-OMS,T-BMP, T-R, T-B), the IRGACURE series manufactured by Ciba SpecialtyChemicals (e.g. IRGACURE 651, IRGACURE 184, IRGACURE 500, IRGACURE 1000,IRGACURE 149, IRGACURE 819, IRGACURE 261), the DAROCUR seriesmanufactured by Ciba Specialty Chemicals (e.g. DAROCUR 1173),4,4′-bis(diethylamino)benzophenone,2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione,1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone,2-benzyl-2-dimethylamino-4-morpholinobutyrophenone,2,2-dimethoxy-2-phenylacetophenone,2-(o-chlorophenyl)-4,5-diphenylimidazolyl dimer,2-(o-fluorophenyl)-4,5-diphenylimidazolyl dimer,2-(o-methoxyphenyl)-4,5-diphenylimidazolyl dimer,2-(p-methoxyphenyl)-4,5-diphenylimidazolyl dimer,2-(p-dimethoxyphenyl)-4,5-diphenylimidazolyl dimer,2-(2,4-dimethoxyphenyl)-4,5-diphenylimidazolyl dimer,2-(p-methylmercaptophenyl)-4,5-diphenylimidazolyl dimer, benzoinisopropyl ether, etc. may also suitably be used.

Furthermore, the photosensitive resin composition of the presentinvention may employ a sensitizer or a light stabilizer in combination.

Specific examples thereof include benzoin, benzoin methyl ether,9-fluorenone, 2-chloro-9-fluorenone, 2-methyl-9-fluorenone, 9-anthrone,2-bromo-9-anthrone, 2-ethyl-9-anthrone, 9,10-anthraquinone,2-ethyl-9,10-anthraquinone, 2-t-butyl-9,10-anthraquinone,2,6-dichloro-9,10-anthraquinone, xanthone, 2-methylxanthone,2-methoxyxanthone, 2-ethoxyxanthone, thioxanthone,2,4-diethylthioxanthone, acridone, 10-butyl-2-chloroacridone, benzil,dibenzylacetone, p-(dimethylamino)phenyl styryl ketone,p-(dimethylamino)phenyl p-methylstyryl ketone, benzophenone,p-(dimethylamino)benzophenone (or Michler's ketone),p-(diethylamino)benzophenone, benzanthrone, a benzothiazole-basedcompound described in JP-B-51-48516, etc., Tinuvin 1130 and 400, etc.

The photosensitive resin composition of the present invention may employanother known initiator in addition to the above-mentionedphotopolymerization initiator.

Specific examples thereof include a vicinal polyketaldonyl compounddisclosed in U.S. Pat. No. 2,367,660, an α-carbonyl compound disclosedin U.S. Pat. Nos. 2,367,661 and 2,367,670, an acyloin ether disclosed inU.S. Pat. No. 2,448,828, an α-hydrocarbon-substituted aromatic acyloincompound disclosed in U.S. Pat. No. 2,722,512, a polynuclear quinonecompound disclosed in U.S. Pat. Nos. 3,046,127 and 2,951,758, acombination of triallylimidazole dimer/p-aminophenyl ketone disclosed inU.S. Pat. No. 3,549,367, and a benzothiazole-basedcompound/trihalomethyl-s-triazine-based compound disclosed inJP-B-51-48516.

From the viewpoint of obtaining the effects of the present inventionmore effectively, the total content of the photopolymerization initiator(C) in the total solids content of the photosensitive resin compositionof the present invention is preferably 1 to 30 wt %, more preferably 2to 25 wt %, and particularly preferably 3 to 20 wt %.

(D) Resin

The photosensitive resin composition of the present invention comprisesa resin as a binder (film-forming agent). This resin is preferably analkali-soluble resin.

As the resin, a linear organic polymer is preferably used. As such a‘linear organic polymer’, any known polymer may be used. In order toenable aqueous development or weakly alkaline aqueous development, alinear organic polymer that is soluble or swellable in water or weaklyalkaline water is preferably selected. The linear organic polymer isselected and used according to an intended application not only as afilm-forming agent but also as an aqueous, weakly alkaline aqueous, ororganic solvent developing agent. For example, when a water-solubleorganic polymer is used, aqueous development becomes possible. Examplesof such a linear organic polymer include radical polymers having acarboxylic acid group in a side chain such as those described inJP-A-59-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957,JP-A-54-92723, JP-A-59-53836, and JP-A-59-71048, that is, a resin formedby homopolymerization or copolymerization of a carboxyl group-containingmonomer, a resin formed by hydrolysis, half esterification, or halfamidation of an acid anhydride unit of a homopolymer or copolymer of anacid anhydride-containing monomer, and an epoxy acrylate in which anepoxy resin is modified with an unsaturated monocarboxylic acid or acidanhydride. As the carboxyl group-containing monomer there can be citedacrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleicacid, fumaric acid, and 4-carboxylstyrene, and as the acidanhydride-containing monomer there can be cited maleic anhydride.

Similarly, there is an acidic cellulose derivative having a carboxylicacid group in a side chain. In addition thereto, one formed by adding acyclic acid anhydride to a polymer having a hydroxy group is alsouseful.

When a copolymer is used as the resin (e.g. an alkali-soluble resin) inthe present invention, a monomer other than the above-mentioned monomersmay be used as a compound that is copolymerized. Examples of said othermonomer include compounds (1) to (12) below.

-   (1) Acrylic acid esters and methacrylic acid esters having an    aliphatic hydroxy group, such as 2-hydroxyethyl acrylate,    2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl    acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,    3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.-   (2) Acrylic acid esters that do not have an aliphatic hydroxy group,    such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl    acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate,    2-ethylhexyl acrylate, octyl acrylate, benzyl acrylate,    2-chloroethyl acrylate, glycidyl acrylate, 3,4-epoxycyclohexylmethyl    acrylate, vinyl acrylate, 2-phenylvinyl acrylate, 1-propenyl    acrylate, allyl acrylate, 2-allyloxyethyl acrylate, and propargyl    acrylate.-   (3) Methacrylic acid esters that do not have an aliphatic hydroxy    group, such as methyl methacrylate, ethyl methacrylate, propyl    methacrylate, butyl methacrylate, isobutyl methacrylate, amyl    methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate,    cyclohexyl methacrylate, benzyl methacrylate, 2-chloroethyl    methacrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl    methacrylate, vinyl methacrylate, 2-phenylvinyl methacrylate,    1-propenyl methacrylate, allyl methacrylate, 2-allyloxyethyl    methacrylate, and propargyl methacrylate.-   (4) Acrylamides and methacrylamides such as acrylamide,    methacrylamide, N-methylolacrylamide, N-ethylacrylamide,    N-hexylmethacrylamide, N-cyclohexylacrylamide,    N-hydroxyethylacrylamide, N-phenylacrylamide,    N-nitrophenylacrylamide, N-ethyl-N-phenylacrylamide,    vinylacrylamide, vinylmethacrylamide, N,N-diallylacrylamide,    N,N-diallylmethacrylamide, allylacrylamide, and allylmethacrylamide.-   (5) Vinyl ethers such as ethyl vinyl ether, 2-chloroethyl vinyl    ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl    ether, octyl vinyl ether, and phenyl vinyl ether.-   (6) Vinyl esters such as vinyl acetate, vinyl chloroacetate, vinyl    butyrate, and vinyl benzoate.-   (7) Styrenes such as styrene, α-methylstyrene, methylstyrene,    chloromethylstyrene, and p-acetoxystyrene.-   (8) Vinyl ketones such as methyl vinyl ketone, ethyl vinyl ketone,    propyl vinyl ketone, and phenyl vinyl ketone.-   (9) Olefins such as ethylene, propylene, isobutylene, butadiene, and    isoprene.-   (10) N-Vinylpyrrolidone, acrylonitrile, and methacrylonitrile.-   (11) Unsaturated imides such as maleimide, N-acryloylacrylamide,    N-acetylmethacrylamide, N-propionylmethacrylamide, and    N-(p-chlorobenzoyl)methacrylamide.-   (12) Methacrylic acid-based monomers in which a hetero atom is    bonded to the α-position, such as compounds described in    JP-A-2002-309057 and JP-A-2002-311569.

Among them, (meth)acrylic resins having an allyl group or vinyl estergroup and a carboxyl group in a side chain, alkali-soluble resins havinga double bond in a side chain described in JP-A-2000-187322 andJP-A-2002-62698, and alkali-soluble resins having an amide group in aside chain described in JP-A-2001-242612 are suitable since the balancebetween film strength, sensitivity, and developability is excellent.

Furthermore, acid group-containing urethane-based binder polymersdescribed in JP-B-7-12004, JP-B-7-120041, JP-B-7-120042, JP-B-8-12424,JP-A-63-287944, JP-A-63-287947, and JP-A-1-271741, and urethane-basedbinder polymers having an acid group and a double bond in a side chaindescribed in JP-A-2002-107918 are advantageous in terms of printingdurability and low exposure suitability since the strength is very good.

Furthermore, acid group-containing acetal-modified polyvinylalcohol-based binder polymers described in European Patent No. 993966,European Patent No. 1204000, and JP-A-2001-318463 are suitable since thebalance between film strength and developability is excellent.

In addition to the above, as a water-soluble linear organic polymer,polyvinylpyrrolidone, polyethylene oxide, etc. are useful. Furthermore,in order to increase the strength of a cured film, an alcohol-solublenylon or a polyether of 2,2-bis(4-hydroxyphenyl)propane andepichlorohydrin is also useful.

In the present invention, among the resins described above, resinshaving a polymerizable group-containing monomer unit and an acidicgroup-containing monomer unit are preferable. As the polymerizablegroup-containing monomer unit, an ethylenically unsaturatedgroup-containing monomer unit is preferable, and a monomer unit havingan acryloyloxy group or a methacryloyloxy group in a side chain is morepreferable. As the acidic group-containing monomer unit, a sulfonic acidgroup- or carboxyl group-containing monomer unit is preferable, and amonomer unit derived from acrylic acid or methacrylic acid ispreferable.

The weight-average molecular weight of the resin contained in thephotosensitive resin composition of the present invention is preferablyat least 5,000, and more preferably in the range of 10,000 to 300,000,and the number-average molecular weight is preferably greater than2,000, and more preferably in the range of 3,000 to 250,000. Thepolydispersity (weight-average molecular weight/number-average molecularweight) is preferably at least 1, and more preferably in the range of1.1 to 10.

These resins may be any of a random polymer, a block polymer, a graftpolymer, etc.

The resin in the present invention may be synthesized by aconventionally known method. Examples of a solvent used in synthesisinclude tetrahydrofuran, ethylene dichloride, cyclohexanone, methylethyl ketone, acetone, methanol, ethanol, ethylene glycol monomethylether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate,diethylene glycol dimethyl ether, 1-methoxy-2-propanol,1-methoxy-2-propyl acetate, N,N-dimethylformamide,N,N-dimethylacetamide, toluene, ethyl acetate, methyl lactate, ethyllactate, dimethyl sulfoxide, and water. These solvents may be used ontheir own or as a mixture of two or more types.

As a radical polymerization initiator used when synthesizing the resinin the present invention, a known compound such as an azo type initiatoror a peroxide initiator can be cited.

The resin content (when two or more types are used, the total content)in the total solids content of the photosensitive resin composition ofthe present invention is not particularly limited, but from theviewpoint of obtaining the effects of the present invention moreeffectively, it is preferably 5 to 50 wt %, more preferably 10 to 40 wt%, and particularly preferably 10 to 35 wt %.

(E) Organic Solvent

The photosensitive resin composition of the present invention comprisesan organic solvent. With regard to the organic solvent (E), one type maybe used on its own or two or more types may be used in combination.

The organic solvent used in the present invention is not particularlylimited as long as the solubility of components (A) to (D) and thecoating properties of the photosensitive resin composition aresatisfied, but it is particularly preferable for selection to be madewhile taking into consideration the dispersibility of the titanium black(A), the solubility of the resin (D), the coating properties, andsafety.

The organic solvent (E) is not particularly limited, and a known organicsolvent may be used; preferred examples thereof include an ester(including a 3-oxypropionic acid alkyl ester and a 2-oxypropionic acidalkyl ester), an ether, a ketone, and/or an aromatic hydrocarbon.

Preferred examples of the solvent that can be used include esters suchas ethyl acetate, n-butyl acetate, isobutyl acetate, amyl formate,isoamyl acetate, isobutyl acetate, butyl propionate, isopropyl butyrate,ethyl butyrate, butyl butyrate, methyl lactate, ethyl lactate, methyloxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate,ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate andethyl ethoxyacetate; 3-oxypropionic acid alkyl esters such as methyl3-oxypropionate and ethyl 3-oxypropionate, for example, methyl3-methoxypropionate, ethyl 3-methoxypropionate, methyl3-ethoxypropionate, ethyl 3-ethoxypropionate, etc.; 2-oxypropionic acidalkyl esters such as methyl 2-oxypropionate, ethyl 2-oxypropionate, andpropyl 2-oxypropionate, for example, methyl 2-methoxypropionate, ethyl2-methoxypropionate, propyl 2-methoxypropionate, methyl2-ethoxypropionate, ethyl 2-ethoxypropionate, methyl2-oxy-2-methylpropionate, ethyl 2-oxy-2-methylpropionate, methyl2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate, etc.;methyl pyruvate, ethyl pyruvate, propyl pyruvate, methyl acetoacetate,ethyl acetoacetate, methyl 2-oxobutanoate, ethyl 2-oxobutanoate, etc.;

ethers such as diethylene glycol dimethyl ether, tetrahydrofuran,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,methyl CELLOSOLVE acetate, ethyl CELLOSOLVE acetate, diethylene glycolmonomethyl ether, diethylene glycol monoethyl ether, diethylene glycolmonobutyl ether, propylene glycol monomethyl ether, propylene glycolmonomethyl ether acetate, propylene glycol monoethyl ether acetate, andpropylene glycol monopropyl ether acetate;

The organic solvent (E) preferably has a boiling point at normalpressure in the range of 100° C. to 180° C., and more preferably in therange of 120° C. to 160° C.

Furthermore, the organic solvent (E) is preferably a glycol monoalkylether carboxylic acid ester. As the glycol monoalkyl ether carboxylicacid ester, propylene glycol monomethyl ether acetate (boiling point146° C.) is preferable.

The amount of organic solvent (E) used in the photosensitive resincomposition of the present invention is preferably an amount that givesa solids content concentration of 2 to 60 wt %, and more preferably 5 to40 wt %.

(F) Other Component

The photosensitive resin composition of the present invention maycomprise (F) another component in addition to (A) to (E) above. As theother component (F), a sensitizer, a co-sensitizer (a supersensitizer),a thermal polymerization inhibitor, an adhesion improving agent, andanother additive can be cited as examples.

Sensitizer

The photosensitive resin composition of the present invention maycomprise a sensitizer.

As the sensitizer, one that sensitizes the above-mentionedphotopolymerization initiator by an electron transfer mechanism or anenergy transfer mechanism is preferable.

As the sensitizer, those belonging to the compound types exemplifiedbelow and having an absorption wavelength in a wavelength region of 300nm to 450 nm can be cited.

That is, examples thereof include polynuclear aromatic compounds (e.g.phenanthrene, anthracene, pyrene, perylene, triphenylene,9,10-dialkoxyanthracene), xanthenes (e.g. fluorescein, eosin,erythrosine, rhodamine B, Rose Bengal), thioxanthones(isopropylthioxanthone, diethylthioxanthone, chlorothioxanthone),cyanines (e.g. thiacarbocyanine, oxacarbocyanine), merocyanines (e.g.merocyanine, carbomerocyanine), phthalocyanines, thiazines (e.g.thionine, methylene blue, toluidine blue), acridines (e.g. acridineorange, chloroflavine, acriflavine), anthraquinones (e.g.anthraquinone), squariums (e.g. squarium), coumarins (e.g.7-diethylamino-4-methylcoumarin), ketocoumarin, phenothiazines,phenazines, styrylbenzenes, azo compounds, diphenylmethane,triphenylmethane, distyrylbenzenes, carbazoles, porphyrin, spirocompounds, quinacridone, indigo, styryl, pyrylium compounds,pyrromethene compounds, pyrazolotriazole compounds, benzothiazolecompounds, barbituric acid derivatives, thiobarbituric acid derivatives,aromatic ketone compounds such as acetophenone, benzophenone,thioxanthone, and Michler's ketone, and heterocyclic compounds such asan N-aryloxazolidinone.

When the photosensitive resin composition of the present inventioncomprises a sensitizer, from the viewpoint of the efficiency of lightabsorption in a deep part and initiation decomposition efficiency, thecontent of the sensitizer in the photosensitive resin composition ispreferably 0.1 to 20 wt % of the weight of the total solids content, andmore preferably 0.5 to 15 wt %.

Co-Sensitizer

The photosensitive resin composition of the present invention maycomprise a co-sensitizer (a supersensitizer).

The co-sensitizer has a function of further improving the sensitivity ofthe photopolymerization initiator or the sensitizer toward actinicradiation, a function of suppressing the inhibition of polymerization ofthe polymerizable compound by oxygen, etc.

Examples of such a co-sensitizer include amines such as compoundsdescribed in M. R. Sander et al., Journal of Polymer Society, Vol. 10,p. 3173 (1972), JP-B-44-20189, JP-A-51-82102, JP-A-52-134692,JP-A-59-138205, JP-A-60-84305, JP-A-62-18537, JP-A-64-33104, andResearch Disclosure No. 33825, and specific examples thereof includetriethanolamine, ethyl p-dimethylaminobenzoate, p-formyldimethylaniline,and p-methylthiodimethylaniline.

Further examples of the co-sensitizer include thiols and sulfides suchas thiol compounds described in JP-A-53-702, JP-B-55-500806, andJP-A-5-142772, and disulfide compounds described in JP-A-56-75643, andspecific examples thereof include 2-mercaptobenzothiazole,2-mercaptobenzoxazole, 2-mercaptobenzimidazole,2-mercapto-4(3H)-quinazoline, and β-mercaptonaphthalene.

Furthermore, other examples of the co-sensitizer include amino acidcompounds (e.g. N-phenylglycine, etc.), organometallic compounds (e.g.tributyltin acetate, etc.) described in JP-B-48-42965, hydrogen donorsdescribed in JP-B-55-34414, and sulfur compounds (e.g. trithiane, etc.)described in JP-A-6-308727.

When the photosensitive resin composition of the present inventioncomprises a co-sensitizer, from the viewpoint of improving the cure rateby means of the balance of polymer growth rate and chain transfer, thecontent of the co-sensitizer is preferably in the range of 0.1 to 30 wt% relative to the weight of the total solids content of thephotosensitive resin composition, more preferably in the range of 1 to25 wt %, and yet more preferably in the range of 0.5 to 20 wt %.

Thermal Polymerization Inhibitor

In the photosensitive resin composition of the present invention, asmall amount of thermal polymerization inhibitor may be added in orderto prevent unnecessary thermal polymerization of the polymerizablecompound during production or storage of the composition.

As the thermal polymerization inhibitor that can be used in the presentinvention, hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol,pyrogallol, t-butylcatechol, benzoquinone,4,4′-thiobis(3-methyl-6-t-butylphenol),2,2′-methylenebis(4-methyl-6-t-butylphenol), N-nitrosophenylhydroxyaminecerium (III) salt, etc. can be cited.

When the photosensitive resin composition of the present inventioncomprises a thermal polymerization inhibitor, the amount of thermalpolymerization inhibitor added is preferably about 0.01 to about 5 wt %relative to the total solids content of the photosensitive resincomposition.

Furthermore, in order to prevent inhibition of polymerization by oxygen,a higher fatty acid derivative such as behenic acid or behenamide, etc.may be added as necessary, the higher fatty acid derivative beinglocalized on the surface of a coating during drying after coating. Theamount of higher fatty acid derivative added is preferably about 0.5 toabout 10 wt % of the total composition.

Adhesion Improving Agent

In the photosensitive resin composition of the present invention, inorder to improve adhesion to a hard surface such as a substrate, anadhesion improving agent may be added. As the adhesion improving agent,a silane-based coupling agent, a titanium coupling agent, etc. can becited.

Examples of the silane-based coupling agent includeγ-(2-aminoethyl)aminopropyltrimethoxysilane,γ-(2-aminoethyl)aminopropyldimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane,γ-acryloxypropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane,γ-isocyanatopropyltriethoxysilane,N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilanehydrochloride, γ-glycidoxypropyltrimethoxysilane,γ-glycidoxypropyltriethoxysilane, aminosilane,γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, vinyltriacetoxysilane,γ-chloropropyltrimethoxysilane, hexamethyldisilazane,γ-anilinopropyltrimethoxysilane, vinyltrimethoxysilane,vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane,octadecyldimethyl[3-(trimethoxysilyl)propyl]ammonium chloride,γ-chloropropylmethyldimethoxysilane,γ-mercaptopropylmethyldimethoxysilane, methyltrichlorosilane,dimethyldichlorosilane, trimethylchlorosilane,2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, bisallyltrimethoxysilane,tetraethoxysilane, bis(trimethoxysilyl)hexane, phenyltrimethoxysilane,N-(3-acryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane,N-(3-methacryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane,(methacryloxymethyl)methyldiethoxysilane, and(acryloxymethyl)methyldimethoxysilane.

Among them, γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane,γ-acryloxypropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-aminopropyltriethoxysilane, and phenyltrimethoxysilane are preferable,and γ-methacryloxypropyltrimethoxysilane is most preferable.

When the photosensitive resin composition of the present inventioncomprises an adhesion improving agent, the amount of adhesion improvingagent added is preferably 0.5 to 30 wt % of the total solids content ofthe photosensitive resin composition, and more preferably 0.7 to 20 wt%.

Other Additive

Furthermore, a known additive such as an inorganic filler, aplasticizer, or an oleophilizing agent may be added to thephotosensitive resin composition of the present invention in order toimprove the physical properties of a cured film.

Examples of the plasticizer include dioctyl phthalate, didodecylphthalate, triethylene glycol dicaprylate, dimethyl glycol phthalate,tricresyl phosphate, dioctyl adipate, dibutyl sebacate, and triacetylglycerol.

The amount of plasticizer added is preferably no greater than 10 wt %relative to the total weight of the polymerizable compound and theresin.

Process for Producing Photosensitive Resin Composition

The photosensitive resin composition of the present invention may beprepared by mixing (A) to (E) above and as necessary (F) othercomponents, and dispersing the titanium black (A) uniformly.

The titanium black is preferably dispersed in advance in a resinsolution in the presence of a dispersion adjuvant. A step of dispersingtitanium black preferably comprises two stages, that is, a step ofkneading in a high viscosity resin solution and subsequently adispersion step of carrying out medium-dispersion using a medium.

As the dispersion adjuvant, the resin (D), a known polymeric dispersant,etc. can be cited.

In the step of kneading the titanium black in the production of thephotosensitive resin composition of the present invention, the titaniumblack and another black color material used in combination, a dispersantand/or a surface-treatment agent, an alkali-soluble resin, and a solventare firstly kneaded. A machine used for kneading is not particularlylimited; examples thereof include a two roll mill, a three roll mill, aball mill, a Tron Mill, a disper, a kneader, a co-kneader, ahomogenizer, a blender, and a single screw or double screw extruder, anddispersion is preferably carried out while applying a strong shearforce.

Subsequently, an organic solvent and a resin (the remaining resin fromthe kneading step) are added. Examples of machines used in thedispersion step mainly include a vertical or horizontal sand grinder, apin mill, a slit mill, and an ultrasonic dispersing machine, anddispersion is preferably carried out using a medium (beads) such asglass or zirconia having a particle size of 0.1 to 1 mm.

The above-mentioned kneading step may be omitted, and in this casemedium dispersion of a pigment, a dispersant and/or a surface-treatmentagent, a resin, and a solvent is preferably carried out. In this case,the remaining resin from the kneading step is preferably added partwaythrough the dispersion.

Details of the kneading step and the dispersion step are described in T.C. Patton, ‘Paint Flow and Pigment Dispersion’ (1964, John Wiley andSons), etc.

(2) Light-Shielding Color Filter

The photosensitive resin composition of the present invention ispreferably used in production of a light-shielding color filter.

The ‘light-shielding color filter’ referred to in the present inventionmeans a light-shielding pattern obtained by providing a coating of aphotosensitive resin composition comprising at least a black colormaterial, a photopolymerizable compound, a resin, a photopolymerizationinitiator, and two or more types of organic solvents, exposing, anddeveloping. The color of the ‘light-shielding color filter’ in thepresent invention may be an achromatic color such as black or gray, orblack, gray, etc. having a chromatic color mixed therewith.

Since the ‘light-shielding color filter’ is obtained by providing acoating of a photosensitive resin composition comprising at least ablack color material, a photopolymerizable compound, a resin, aphotopolymerization initiator, and two or more types of organicsolvents, exposing, and developing, it may be interchangeably called alight-shielding film or a light-shielding filter.

The light-shielding color filter preferably has an average transmittanceof no greater than 10% in the visible region and the IR region (400 to1,600 nm), and more preferably no greater than 1%.

The light-shielding color filter is preferably provided in alight-shielding section on the periphery of an image pickup section ofan image sensor and/or a light-shielding section on a reverse faceopposite to the surface with the image pickup section.

By enhancing the light-shielding properties of the light-shieldingsection on the periphery of the image pickup section and/or the reverseface of the image pickup face, it is possible to reduce dark currentgenerated in an area other than the image pickup section, and improvethe photoelectric conversion function in passing through the colorfilter disposed on the image sensor.

Furthermore, in the present invention, the optical density of alight-shielding color filter formed using the photosensitive resincomposition is preferably at least 2 but no greater than 10, morepreferably at least 3 but no greater than 10, and particularlypreferably at least 4 but no greater than 9.

The film thickness of the light-shielding color filter is notparticularly limited, but from the viewpoint of obtaining the effects ofthe present invention more effectively, it is preferably 0.1 μm to 10μm, more preferably 0.3 μm to 5.0 μm, and particularly preferably 0.5 μmto 3.0 μm.

The size (length of one side) of the light-shielding color filter is notparticularly limited, but from the viewpoint of obtaining the effects ofthe present invention more effectively, it is preferably at least 200μm, more preferably at least 500 μm, and particularly preferably atleast 1,000 μm. The upper limit thereof is not particularly limited, butis preferably 10,000 μm.

Furthermore, the area of the light-shielding color filter is notparticularly limited, but from the viewpoint of obtaining the effects ofthe present invention more effectively, it is preferably at least 0.05mm², more preferably at least 0.2 mm², and particularly preferably atleast 1 mm². The upper limit thereof is not particularly limited, but ispreferably no greater than 9 mm².

The light-shielding color filter of the present invention may suitablybe used in an image sensor such as a CCD or a CMOS, and it isparticularly suitable for an image sensor such as a CCD or a CMOS havinggreater than 1,000,000 pixels.

(3) Process for Producing Light-Shielding Color Filter

A process for producing the light-shielding color filter of the presentinvention is not particularly limited, and preferably comprises (a) astep of coating a substrate with the photosensitive resin composition ofthe present invention (photosensitive layer formation step), (b) a stepof imagewise exposing (exposure step), and (c) a step of developing toform a pattern (development step).

Each step of the process for producing the light-shielding color filterof the present invention is explained below.

(a) Photosensitive Layer Formation Step

In the photosensitive layer formation step, a photosensitive layer isformed by coating the top of a substrate with the photosensitive resincomposition of the present invention.

Examples of a substrate that can be used in this step include aphotoelectric transducer substrate such as a silicon substrate used inan image sensor, etc., and a complementary metal oxide semiconductor(CMOS).

Furthermore, an undercoat layer may be provided on the top of thesesubstrates as necessary in order to improve adhesion to an upper layer,prevent diffusion of a material, or planarize the surface of thesubstrate.

As a method for coating the top of a substrate with the photosensitiveresin composition of the present invention, various types of coatingmethods such as slit coating, an inkjet method, spin coating, castcoating, roll coating, and a screen printing method may be employed.

With regard to the coating thickness of the photosensitive resincomposition, from the viewpoint of resolution and developability it ispreferably 0.35 μm to 3.0 μm, and more preferably 0.50 μm to 2.5 μm.

The photosensitive resin composition applied onto the substrate isusually dried under conditions of 70° C. to 110° C. for on the order of2 min to 4 min, thus forming a photosensitive layer.

(b) Exposure Step

In the exposure step, the photosensitive layer formed in thephotosensitive layer formation step is exposed and cured. In the presentinvention, the exposure step is preferably a step in which exposure iscarried out through a mask, and more preferably is a step in whichexposure is carried out through a photomask. When exposure is carriedout through a mask, it is preferable to cure only a coating portion thatis irradiated with light.

Exposure is preferably carried out by irradiation with radiation; asradiation that can be used when carrying out exposure, in particular, UVrays such as g rays (436 nm) and i rays (365 nm) are preferably used, irays are more preferably used, and as a light source thereof, a highpressure mercury lamp is preferable. The irradiation intensity ispreferably 5 mJ to 1,500 mJ, more preferably 10 mJ to 1,000 mJ, and mostpreferably 10 mJ to 800 mJ.

(c) Development Step

Subsequent to the exposure step, an alkali development treatment(development step) may be carried out.

In the development step, a portion that has not been exposed in theexposure step is leached in an alkaline aqueous solution. This leavesonly a portion that has been photocured.

As a developer, an organic alkali developer that does not cause anydamage to a circuit, etc. on a base is desirable. The developmenttemperature is usually 20° C. to 30° C., and the development time is 20to 90 sec.

As the alkali used in the developer, an alkaline aqueous solution inwhich an organic alkaline compound such as aqueous ammonia, ethylamine,diethylamine, dimethylethanolamine, tetramethylammonium hydroxide,tetraethylammonium hydroxide, choline, pyrrole, piperidine, or1,8-diazabicyclo[5.4.0]-7-undecene is diluted with pure water so as togive a concentration of 0.001 to 10 wt % and preferably 0.01 to 1 wt %is used. When a developer comprising such an alkaline aqueous solutionis used, washing (rinsing) with pure water is generally carried outafter developing.

In the process for producing a light-shielding filter for the imagesensor of the present invention, after the above-mentionedphotosensitive layer-formation step, exposure step, and development stepare carried out, a curing step of curing by heating and/or exposing thepattern formed may be carried out as necessary.

A heating step (post bake treatment) subsequent to the development stepis heating after development in order to complete curing, and it ispreferable to carry out heating at 180° C. to 250° C. (hard bake). Thispost bake treatment may be carried out for the coating liquid afterdevelopment continuously or batchwise using heating means such as a hotplate, a convection oven (hot air circulation type dryer), or a highfrequency heater under the above-mentioned temperature conditions.

Furthermore, in combination with or independently from theabove-mentioned post bake treatment, irradiation with UV rays may becarried out using a high pressure mercury lamp, etc., thus curing acolored pattern (post cure treatment).

(4) Image Sensor

The photosensitive resin composition of the present invention maypreferably be used for an image sensor (a solid-state image sensor).Specifically, after the photosensitive resin composition of the presentinvention is provided by coating over a substrate as a thin film, alight-shielding color filter having a desired shape may be produced byimagewise exposure by means of i rays, etc. and development to form apattern.

As hereinbefore described, the light-shielding color filter means afilter having an average transmittance of no greater than 10% in thevisible region and the IR region (400 to 1,600 nm), and preferably nogreater than 1%.

The image sensor of the present invention comprises the light-shieldingcolor filter of the present invention.

The image sensor of the present invention is not particularly limited aslong as it comprises the light-shielding color filter of the presentinvention and functions as an image sensor.

As a preferred example of the image sensor of the present invention,there can be cited an image sensor in which the light-shielding colorfilter of the present invention is disposed on the periphery of an imagepickup section. Since a light-shielding section is disposed on theperiphery of the image pickup section, noise can be reduced, and colorreproduction can be improved.

As another preferred example of the image sensor of the presentinvention, there can be cited an image sensor in which thelight-shielding color filter of the present invention is on a face onthe opposite side to an image pickup section-forming face of a substrateof the image sensor.

The image sensor is explained below by reference to drawings.

FIG. 1 is a sectional view showing one example of an image pickupsection and a light-shielding section disposed on the periphery in theimage sensor of the present invention. FIG. 1 illustrates one example ofthe image sensor having a light-shielding color filter formed byphotocuring the solids content of the photosensitive resin compositionof the present invention on the periphery of a color filter made up ofthree primary color pixels.

An image sensor 1 shown in FIG. 1 has a photoelectric transducer(light-receiving sensor section) 12 on a silicon substrate 10.Furthermore, transfer electrodes (14 a, 14 b) for transferring generatedcharge are provided adjacent to the photoelectric transducer 12. Thesetransfer electrodes 14 a and 14 b are covered with an insulating film16.

Color filters (4R, 4G, 4B) in which three primary color pixelscomprising three primary colors of R (red), G (green), and B (blue) areregularly arranged are disposed on the photoelectric transducer 12, thusforming an image pickup section 2. A light-shielding section 3comprising a light-shielding color filter 5 formed by photocuring thephotosensitive resin composition of the present invention is formed onthe periphery of the image pickup section 2.

In FIG. 1, the CCD or CMOS etc. photoelectric transducer 12, transferelectrodes 14 a and 14 b, planarization layer 18 a, etc. necessary asthe image sensor 1 may be formed in accordance with a known productionprocess. The color filters (4R, 4G, 4B) and the light-shielding colorfilter 5 may be formed by a photoresist technique. A planarization layer18 b may also be formed on the color filters (4R, 4G, 4B). It ispreferable to provide a microlens 17 over the color filters (4R, 4G, 4B)for the purpose of focusing.

A photosensitive resin composition comprising titanium black as alight-shielding agent for visible light and IR light is applieduniformly over the silicon substrate 10 and is heated, thus forming adry coating. Subsequently, a pattern of the light-shielding color filter5 may be obtained by exposing this dry coating using a commercial i raystepper, etc. via a mask with a mask pattern formed thereon so as toopen the image pickup section 2 and cover a photoelectric transducer,etc. used for measuring dark current, followed by alkali development,rinsing with water, and drying.

After the planarization layer 18 b and the microlens 17 are formed asnecessary on the substrate thus obtained, dicing and packaging arecarried out, thus giving the image sensor 1.

In this process, the film thickness from the surface of the siliconsubstrate to the lower surface of the microlens is preferably no greaterthan 5 μm, more preferably no greater than 4.5 μm, and particularlypreferably no greater than 4 μm.

In the image sensor of the present invention, as described above, it ispreferable to dispose a light-shielding color filter on the periphery ofthe image pickup section on the front face side as well as to dispose alight-shielding color filter on the reverse face opposite to the facewhere the image pickup section is present.

More particularly, in an image sensor having on the reverse face of theimage sensor a plurality of protruding electrodes for connecting to awiring board, it is preferable for it to comprise a light-shieldingcolor filter on the reverse face in a region other than the protrudingelectrodes.

Conventionally, in an image sensor having protruding electrodes on thereverse face, stray light enters the interior of the image sensorbetween the image sensor and the image sensor wiring board, thusgenerating dark current, and a picked-up image tends to deteriorate.

The image sensor of the present invention preferably comprise alight-shielding color filter on the reverse face in order to preventstray light from entering. Furthermore, by preventing stray light fromentering, even if injection, etc. of a light-shielding underfill resinfor preventing stray light from entering, which is conventionallycarried out, is omitted, it is possible to suppress generation of darkcurrent due to stray light from the reverse face side, and improve colorreproduction.

Referring to FIG. 2 and FIG. 3, a preferred embodiment of the imagesensor of the present invention is explained. FIG. 2 is a schematicdiagram showing one example of the image sensor of the presentinvention. FIG. 3 is a sectional view along A-A′ in FIG. 2.

An image pickup device (a solid-state image pickup device) 20 as shownin FIG. 2 comprises an image sensor 24 comprising an image pickupsection 2, a light-shielding section 3, and a bonding pad 30.

FIG. 3 is a sectional view of the image pickup device 20 comprising theimage sensor 24 shown in FIG. 2 and its wiring board 21. The imagesensor 24 comprises the image pickup section 2 and the light-shieldingsection 3 on the surface, and comprises a light-shielding color filter23 and a protruding electrode 26 on the reverse face. Furthermore, itmay comprise an underfill resin 25 between the image sensor 24 and thewiring board 21 for the purpose of improving durability and preventingstray light.

A through electrode 27 is formed underneath the bonding pad 30 formed onthe image sensor 24, and is connected to the protruding electrode 26provided on the reverse face of the image sensor 24.

The image sensor 24 may be connected to the wiring board 21 via theprotruding electrode 26, a plurality of which may be formed. Theprotruding electrode 26 is not limited, and a known electrode may beused, examples thereof including a solder ball, a gold stud bump, and agold plated bump.

When the light-shielding color filter 23 is disposed on the reverse faceof the image sensor 24 of the present invention, dark current, which isgenerated by picked-up light entering the image sensor as stray light,can be suppressed.

In accordance with the present invention, there can be provided aphotosensitive resin composition that can form a light-shielding colorfilter having excellent resolving power, excellent adhesion to asubstrate, and excellent coating thickness uniformity on a substrate, alight-shielding color filter formed by using the photosensitive resincomposition and a production process therefor, and an image sensorcomprising the light-shielding color filter.

EXAMPLES

The present invention is explained more specifically below by referenceto Examples, but the present invention is not limited by the Examplesbelow. ‘Parts' and percentage (%)’ are on a weight basis unlessotherwise specified.

1) Preparation of Titanium Black-Containing Black Negative Type CurableComposition

In the composition shown below, each compound was mixed and dissolved,thus giving a photosensitive composition.

Example 1

Preparation of Titanium Black Dispersion

The composition below was first subjected to a high viscosity dispersiontreatment using a two roll mill. The dispersion here had a viscosity of40,000 mPa·s.

Kneading may be carried out by a kneader for 30 minutes prior to thehigh viscosity dispersion treatment.

Composition of Titanium Black Dispersion

Titanium black 13M-T (Jemco Inc.) 40 partsPropylene glycol monomethyl ether acetate solution of benzylmethacrylate (BzMA)/methacrylic acid (MAA) copolymer (BzMA/MAA=70/30(molar ratio), Mw:

30,000, solids content 40 wt %) 6 parts Solsperse 5000 (Zeneca) 1 part 

Component (A) below was added to the dispersion thus obtained, andstirring was carried out for 3 hours by a homogenizer under conditionsof 3,000 rpm. The solution mixture thus obtained was subjected to adispersion treatment by a disperser (Dispermat, manufactured byGetzmann) employing 0.3 mm zirconia beads for 4 hours, thus giving atitanium black dispersion. The viscosity of this dispersion was 8.0mPa·s.

Component (A)

Propylene glycol monomethyl ether acetate solution of benzylmethacrylate BzMA)/methacrylic acid (MAA) copolymer (BzMA/MAA=70/30(molar ratio), Mw:

30,000, solids content 40 wt %)  10 parts Organic solvent (propyleneglycol monomethyl ether acetate) 140 partsPreparation of Photosensitive Resin Composition

Methyl methacrylate/methacrylic acid copolymer (J-1 below)  6.1 partsDipentaerythritol hexaacrylate (T-1 below)  4.8 parts Ethoxylatedpentaerythritol tetraacrylate (T-2 below)  1.7 parts Titanium blackdispersion prepared above   67 parts Propylene glycol monomethyl etheracetate (PGMEA) 15.7 parts Photopolymerization initiator  1.7 parts J-1

T-1

T-2

As the 1.7 parts of photopolymerization initiator in Examples 1 to 3 andComparative Examples 1 to 3, the compounds shown below were used at theratios by weight shown below.

-   Example 1: I-1/I-2 (50/50)-   Example 2: I-1/I-2 (75/25)-   Example 3: I-1/I-4 (75/25)-   Comparative Example 1: I-4/I-5 (75/25)-   Comparative Example 2: I-1 alone-   Comparative Example 3: I-4 alone-   I-1:    1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone    (K-1 above)-   I-2: 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione    (K-88 above)-   I-3:    2-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-4-(4-chlorophenylthio)-1,2-butanedione    (K-2 above)

Preparation of Light-Shielding Color Filter and Evaluation Thereof

The photosensitive composition thus obtained was applied on a siliconwafer by spin coating, and subsequently heated on a hot plate at 120° C.for 2 minutes.

Subsequently, exposure was carried out by an i ray stepper with a 3 mmsquare pattern from 100 mJ/cm² to 1,000 mJ/cm² in steps of 100 mJ/cm².

After irradiation, puddle development was carried out using a 0.3%aqueous solution of tetramethylammonium hydroxide (CD-2060, manufacturedby FUJIFILM Electronic Materials Co., Ltd. (FFEM)) at 23° C. for 60 sec.Subsequently, rinsing with water was carried out by a spin shower.

Evaluation of Adhesion

The pattern thus obtained was examined by optical microscope andcritical dimension SEM, adhesion was evaluated, and the sensitivity atwhich good adhesion was observed was measured.

Poor adhesion means that the pattern itself peeled off, or peeling orchipping was found even in a portion of the pattern. That is, thesensitivity at which good adhesion was observed means the amount ofexposure at which the pattern showed no peeling or chipping at all.

Evaluation of Coating Thickness Uniformity

An 8 inch silicon wafer was coated with the photosensitive resincomposition at 1,500 rpm (film thickness 2.0 μm), the film thickness ofa central portion and the film thickness of a portion near the edge weremeasured, and the difference therebetween was calculated and was used asan index for uniformity of coating thickness. The smaller the value, thebetter the coating uniformity.

Evaluation of Resolving Power

The photosensitive composition thus obtained was applied on a siliconwafer by spin coating, and subsequently heated on a hot plate at 120° C.for 2 minutes.

Subsequently, exposure was carried out by an i ray stepper using a maskwith 50 μm, 20 μm, 15 μm, 10 μm, and 5 μm cutout patterns (Bayerpattern) at the above amount of exposure for good adhesion plus 100mJ/cm².

After irradiation, puddle development was carried out using a 0.3%aqueous solution of tetramethylammonium hydroxide (CD-2060, manufacturedby FFEM) at 23° C. for 60 sec. Subsequently, rinsing with water wascarried out by a spin shower.

The pattern thus obtained was examined by critical dimension SEM, andresolving power was evaluated. The minimum size at which a clear patterncould be resolved was defined as resolving power.

TABLE 1 Coating Sensitivity for which thickness Resolving good adhesionwas uniformity power observed (mJ/cm²) (Δμm) (μm) Example 1 300 0.05 5Example 2 400 0.05 5 Example 3 400 0.07 10 Comparative Example 1 4000.09 15 Comparative Example 2 600 0.15 50 Comparative Example 3 700 0.1550

What is claimed is:
 1. A photosensitive resin composition comprising atleast: (A) titanium black; (B) a polymerizable compound; (C) aphotopolymerization initiator; (D) a resin; and (E) an organic solvent,the photopolymerization initiator (C) comprising in combination two ormore types of oxime-based photopolymerization initiators including atleast 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone.2. The photosensitive resin composition according to claim 1, whereinthe photopolymerization initiator (C) comprises in combination2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanoneat a molar ratio of 1/9 to 9/1.
 3. The photosensitive resin compositionaccording to claim 1, wherein the titanium black (A) has a content of 10to 60 wt % of the total solids content of the photosensitive resincomposition.
 4. The photosensitive resin composition according to claim1, wherein the photopolymerization initiator (C) has a total content of1 to 30 wt % of the total solids content of the photosensitive resincomposition.
 5. A light-shielding color filter comprising a patternformed by using the photosenitive resin composition according toclaim
 1. 6. An image sensor comprising the light-shielding color filteraccording to claim
 5. 7. A process for producing a light-shielding colorfilter, the process comprising: a step of coating a substrate with thephotosensitive resin composition according to claim 1; a step ofimagewise exposing; and a step of developing to form a pattern.